RE: What changes would you like to see in communities ?

It could be nice to see some sort of frequency metric to see how many times a person has used the community; maybe not the exact number but some sort of marker that indicates a frequent user. It could also be something that users like to see as well, sort of like showing their level of support for that particular community. I'm not sure if that's possible though.

I see that's interesting, definitely possible but I'll need to look into it more to see how to implement it

Also, I don't really like seeing first tags like curangel and appreciator et cetera. I'd rather see a first tag relating specifically to the post content. Is it possible to auto-enforce use of one of the tags the community has specified as acceptable as the first tag?

Yes, but I'm not sure how useful that feature is tbh, this seems like a pet peeve rather than an actual issue