A floating habitat on Venus is harder and less attractive in every way than a rotating space station, which is clearly our next milestone in space. In terms of planets though, there's a reason Mars gets the most attention: it's obviously the best choice.
Getting back from Venus after just beginning to colonize it may not be possible with current technology.
But as things are, the relative effort to terraform Venus, compared with Mars, is absolutely colossal. It essentially requires a full-blown robotic asteroid mining industry, wherein olivine asteroids are diverted directly to Venus, and magnesium and calcium are mined, sent to Jupiter to produce saturated hydrides, and those sent on to Venus. It will take 1000 years, minimum.
Mars can get realistic results within 200 years, just by diverting water-ice comets and managing temperature.
These were called Belters (as in asteroid belt) in the excellent book series The Expanse, which is also an excellent sci-fi show available on Amazon.
That is, develop general AI with a sense of responsibility and filial duty to its parent species, and which won't turn us all into paper clips.
Then you have the Old Man's War universe where the soldiers have engineered bodies and synthetic blood that they have control over (they can explode mosquito like creatures that try to feed on them as an example).
B. V. Larson's Star Force series sees characters changed by both nano bots and specifically-grown intelligent (as a colony) vats of bacteria.
Many science fiction series involve brain backus. If I'm not mistaken Peter F. Hamilton has them in his Commonwealth Saga and the Altered Carbon books and show have it. As does the previously mentioned Old Man's War series by Scalzi.
Daniel Suarez's book (his near-future hard science fiction books are quite good) Change Agent involves lots of serious genetic engineering, including changing one's entire appearance (rather dangerously) with a virus.
I think if we can manage to stay alive long enough as a species, we will be able to at least do everything except for the nano bots and possible even those if we get some significant physics and computational breakthroughs.
As a pre-teen in the mid 1990's a friend and I wanted to turn ourselves into anthropormphic creatures not unlike the creatures in the Island of Dr. Moreau (I believe it was actually the 1996 film adaptation that gave us the idea) and figured somehow a bacteriophage could be created to alter a host at a cellular level but we figured you'd need to find a way to selectively edit genes (that now exists with CRISPR and the like), suppress the immune system to prevent death from it overreacting during the process, and control the replication rate so the body wouldn't burn up with fever or have some sort of energy issue. If a couple of bored pre-teens could think that up while playing a MUD one afternoon, someone someday is going to start really tinkering with humans at a serious scale. It's already being done by biohackers.
Pretty sure this was in some book in the Old Man's War series
I read entirely too much hard science fiction to remember what comes from where, it's why as much as I'd love to I'll never write a space opera. I'd constantly be afraid I was unintentionally plagiarizing multiple authors.
The Belters lived in the Asteroid Belt, and were opposed to both the Terrans and the Martians. The Belters were the most different biologically because the gravity is so low, whereas the Martians got to enjoy the relatively high 1/3 g gravity of Mars.
Any of those projects of colonization in space is even greater waste of resources, compared to colonies in northern Canada, Antarctica, artificial islands or underwater cities.
However, it does seem like building rotating space stations (like O'Neil cylinders) is much more feasible.
Is that true? I can't see how that'd be true, unless maybe you are considering aerobraking to enter mars orbit and parachutes for landing on the surface (?)
Solar power and batteries should work assuming you're willing to build your base among the "peaks of [near] eternal light" which get sunshine nearly ninety percent of the time.
Mars is better for solar power because you won't need nearly as much battery capacity, as you get light on a ~24 hour cycle same as Earth. The Moon with its slow rotation is much more challenging.
Compress that into a tank and you can chemically (or biologically) convert that into an oxygen-nitrogen atmosphere to breathe.
Oh...that's all. So let's ignore for just a second the logistical advantages of figuring out how to actually mount a manned mission to build something non-trivial on another body when you're 3 days away, not 6 months away. Pretend that isn't important.
The moon has water, raw materials, enough gravity things don't just float away, abundant solar and we've already figured out how to get people there and back. We already have an MVP to build on.
On the other hand, a manned Mars mission is still an un-funded wank-fantasy with a disturbingly high failure rate for the unmanned attempts.
By your logic, it seems like we should just give up on building any bases in this solar system altogether, and just start building a ship to go to Alpha Centauri.
Obviously 3 days is better than 6 months. A lot more can be done with a shorter window. I just don't think it justifies passing up all the upsides Mars has to offer
On top of that, the Moon has proven mineral resources which can be mined and refined on-site a lot easier than trying to do the same on Mars.
Mars is just too far away. If you're going to neglect distance, then we should just skip Mars and go straight to Alpha Centauri or some other star with a bunch of exoplanets.
If you have a critical failure on the moon, you are home in 3-4 days being debriefed. If you have a critical failure on Mars, it could be 2 years until your remains can be recovered and respectfully laid to rest.
If you're testing a new technology and discover some serious flaw or major way to improve it and lack the materials to make an adjustment you could have that done and sent on the next trip in a week or a month or 3 months from Earth to the Moon. On Mars, you could be looking at 2+ years.
On the moon you have to deal with power over a 13.65 day night, at first this could be achieved by simply having human missions only there for 2 weeks ~ at a time until you get enough power generation there (say a small reactor) to provide sufficient power constnatly. On Mars you have to deal with a night comparable in length to Earth but you have considerably reduced solar irradiance meaning if you use PV it's always going to produce less during the day. This makes the Moon a better candidate for testing power management, battery technologies, small reactors, etc.
Any technology that can survive in the harsher conditions of the moon, will mostly work out of the box on Mars with the only real stuff needing custom-tailored being vehicles as the Martian and luanr regolith will vary enough (especially combined with the gravity differences) to require you to at least adjust suspensions and wheels.
Mars: -inhospitable temperatures not suitable for human or plant life -explosive decompression due to a micro-meteorite causing a hole -no atmosphere to protect against radiation or projectiles -weak magnetic field providing no protection -violent unpredictable wind storms on the surface -unbreathable atmosphere -the escape velocity from Mars requires a massive rocket equivalent to the one we use to leave Earth and therefore more fuel leaving less payload for delivering other resources or supplies -the distance is 6 months to 1 year depending on the window of opportunity, leading to some NASA scientists to suggest we should find it acceptable that it as a suicide mission with no hope of return
Rotating space station: -high risk from impacts -no atmosphere to protect against radiation or projectiles -no magnetic field providing no protection -danger from space debris from previous missions -no surrounding breathable atmosphere -close distance makes resupplying and re-crewing more tenable -requires constant fuel and attention to not de-orbit -does not establish a permanent residence -not a base of significant distance for further operations to the rest of the solar system
Starting at about 8M55S he decribes some interesting aspects of the so called two day orbit.
Anyways, it is OUTSIDE the magnetic field. But would it really matter if you have the technology to build a space station big enough to have rotational gravity? I'd imagine we'd cover that with regolith mass driven from the moon, or something like that.
Wait, what? Isn't escape velocity from Mars lower than that from Venus? The surface gravity is far lower on Mars.
I also note that you list "no surrounding breathable atmosphere" as a negative for a rotating space station, but the surrounding atmosphere on Venus isn't exactly breathable either...
We just need a craft that can thrust that strength for three days straight.
https://www.johndcook.com/blog/2012/08/30/flying-to-mars-in-...
and
https://larouchepub.com/other/2019/4622-revolutionary_space_...
And at NASA:
https://www.nasa.gov/pdf/501329main_TA02-InSpaceProp-DRAFT-N...
https://futurism.com/nasas-new-ion-thruster-breaks-records-c...