Yeah I work in the Midwest and have been learning .NET for a project I was recently onboarded on. C#/.NET has a stronghold in most enterprise companies out here.
That's interesting. The .NET Core experience shows a lot of promise. I'd fear getting into an old school .NET shop almost as much as I'd fear getting into a "stuck in Java <= 1.7" shop.
No need, just code a fully compatible alternative implementation. It's very unclear what is the situation with Mono (unlike alternative JVM implementations).