Earlier quoted context omitted.
You've basically described C#: Getters, setters fixed? Check. Functional features? Check. Most crappy OO features fixed? Check. Trendy package system inspired by npm/apt-get/gems? Check. Healthy community with libraries replacing frameworks? Check. I'd recommend checking it out if you haven't already.
Has the Mono story gotten better? How feasible is it to develop without thousands of dollars of Microsoft software these days?
Basically, YMMV.
To develop, sure, it is feasible (I did this, but for a simple webservice), but it may be missing something essential to you.