I hope to see Sublime eventually released under a free software license. I'd donate to that project.
I'd be able to function without intellij ultimate but it would be incredibly painful and I'd permanently be slower.
I still use VIM often enough to stay proficient with it, mostly via SSH, but I'll happily use the closed source IDEA editors when they are available.
Depends what you're doing, I suppose. If you're doing web development, Python, Ruby, PHP, C, JavaScript, etc... I don't think being on any particular OS is more important than your tools.
If you are like my parents that can't get on the internet if the browser icon disappears from their desktop, then there might be a problem.
When you use emacs or vim, which import their 1970s / early 1980s OS conventions with their keyboard shortcuts, you realize you can be dropped into a very foreign 'defaults' context, and they can conflict.