I know the help is geared towards asking questions but largely speaking, the same applies to answers. Whatever your personal views on the matter Mint isn't Ubuntu in a similar way that Ubuntu isn't Debian. This limitation may seem arbitrary from the outside but it's a founding distinction between us and other SE network sites (Unix & Linux, Super User, Server Fault, etc).
That said, looking at the things you have answered, you are picking topics that would largely apply to any version of 14.04 (official or not).
I think you're right, I think Mint probably is taboo here and that most people take a shoot-on-sight approach to it. We usually see "Mint" in a question setting and that makes us all the more ready to close/delete posts mentioning it.
So why mention Mint at all? If you can limit yourself to answering things that definitely apply to both Ubuntu and Mint, I can't see why your contributions wouldn't be welcome.