Spain is increasing taxes and they already were pretty hefty for Limited Liability companies.
Portugal is similar on paper but it's easier to start, and their tax agency is not nearly as punitive and arbitrary as the Spanish one.
And you'll have sun (in the south), contained prices and polite Portuguese, which tend to speak decent English, in case you need hiring.
Portuguese infrastructures and utilities are still far below Spain, specially roads and highways, but Portugal is slowly improving while Spain has been declining for a while and it's basically walking to a cliff.
Goin on a Travel to Spain is pretty easy too.
I'm Spanish, if anyone thought I was advertising my country.
If you go to neighborhoods where the locals live or outside the city limits you'll see the price drop considerably. A friend is living one hour away from here and paying 600 EUR for a nice house that's four times the size of my apartment.
Presumably you go to large cities for the social interaction.
On the other hand, living in Spain and speaking fluent English can be almost like a superpower in some circumstances.
(And for the record, my native language is Spanish)
And although I wouldn't worry too much about language too much if your focus is primarily on work, Spanish is perhaps the easiest language to learn as an English speaker. You can achieve professional level fluency in 600 hours of study. Certainly with 80-100 hours of concentrated study and continued practice after that you can learn more than enough to get by in daily life.
Two big advantages with learning Spanish: 1) pronunciation is easy to learn and is the same for both written and spoken Spanish; 2) there are lots of cognates, so if your English vocabulary is good then you already know lots of Spanish words.
Spain is great, but for the purposes of picking a country for working remotely and having a longer runway, I would argue heavily for Mexico over Spain if you're picking a Spanish speaking country. The overall cost of living is low, internet access can be great depending on the area, you'll be on a similar timezone as the US, and services (cooking, laundry, babysitting, etc) are very inexpensive - leaving you with much more time to work (or to use your downtime more effectively than running errands/etc).
Both are pretty easy, though, and Spanish opens up a lot more of the world. But Italian is just so darn fun :)
Your impressions are correct. While some violence is greatly exagerated to paint a picture (For instance, Chicago, St Louis, Baltimore, Washington are more violent than São Paulo or Rio de Janeiro), it still is MUCH safer in Europe or Sillicon Valley/New York.
Barcelona is awesome and it's cheap (spent a total of $800 for the whole month on food, living, etc.). Highly recommend for someone on a budget who wants to hack away.