Basically a casual ask for "can you share how many options are outstanding?" is about as good as you are going to get. Totally good. Non-stand demands? Not so good.
If the VC has preferential shares (they do) just realize that's ok - and probably fair. Don't join the company if you don't think it can exit above it's funding amounts if you are in for the stock - but hopefully you're in it because you really will love the position and the stock is just a bonus if it makes it.
That's the most important thing :) You don't want to be in a job you don't like just because it's profitable IMHO.
It's tricky to share that with employees and not have it get out.
That being said, if it were all public, I think that would be fine, I'm not sure what results that would cause if every company did that, and it might be cool if every company were required to by law (hint, hint, congress!).
And absolutely none of them are valid. If you're going to have this person work on the core of your company, there is absolutely no reason to not be up front with them.
I do however strongly believe in tempering expectations, it's wrong to try to retain people by thinking they have more than they do.
It will influence your relationship, positively.
Executives and managers always pay attention to these details and negotiate them when joining a company. The fact that you're paying attention signals that you actually understand what's going on and demands respect.
Some companies will refuse to give you this info and resent you for asking, but you should automatically reject such offers.
If a "rank and file" developer goes back and forth grilling them over offer terms, and is exceptionally picky above his peer group, this DOES make it back upstream in negative ways.
Some companies will not give you this as a matter of policy - , if you are ok with the salary, you could still enjoy working there - and may also make a great deal of money (or you might not).
Then don't work for those companies.
Ones goal in life should not be to get exploited at shitty startups as a "rank and file" developer (aka chump).
All being said, if at that stage of a job offer, you don't want to be looking like the most important thing to you are your options. If you get a decent salary and like the work, you are not being exploited.
The approach you imply is the approach I've taken. Work with founders that I trust, verify the details of the deal to the best of my ability and assume that good people do the right thing for other good people.