One thing to be said about Microsoft and their products is that they probably support what you want to do. It may cost you an arm and a leg, but it's probably supported (as with most high-end enterprise products, I find). It's easy to see how this came about, too. "We have a multi-million dollar sale on our hand, but they really want feature X. Guess we can subsidize the development with that sale."
I feel like cost has only really become an issue recently with their drive to get everyone in the cloud or on Azure and even then it's only an issue for small businesses. They offer ridiculous discounts to nonprofits and in education settings it's basically free.
Yes.
https://msdn.microsoft.com/en-us/library/ms151196.aspx
https://msdn.microsoft.com/en-us/library/ms151855.aspx