> if you had to pick a vendor today, which one would you go with and why?
Depends on what you need. But if forced to pick with no other context, I'd pick AWS. It's like the MS Windows of the 1990s--lots of momentum and tons of work.
> Is [Azure] still that way?
No first hand experience.
> Do you pick a solid vendor and then go with it or pick something that is full of weird gotchas and troubles and demand a higher price for that very reason?
Depends? Do you want to be the person maintaining the COBOL or perl program before the lights go out? Or pushing boundaries/doing new work? Both will pay the bills. I'd go with solid vendor myself, as it'd be more fun for me.
> 4. ...
No first hand experience.
> 5. ...
I don't understand the q.