It's definitely slowed down, but that's fine, let it grow naturally. Personally I sometimes get put off because I end up seeing the same posts repeated across different instances so it can be harder to find content, but I also love the smaller community.
It is literally a zip file. If I remember correctly you have to write some xml which describes the layout of the skin and then include any images you need, you then zip it and change the file extension to wsz.
So really you could put anything in a skin.
I doubt it will ever happen but it would be amazing if I could just have one messaging app and message whomever I want on whatever platform I wanted, without having to using some crazy bridges.
I've said this before, the thing I hate about reddit and discord is that you only get exposed to "current" threads or "top" threads. On old forums everything was just there and if someone commented on it, it came back to the top and re-ignited conversations.
I was a big user of the command and conquer forums and I definitely miss the community of it. But that may just be the scale of Internet then compared to now. Back then you saw the same users every day and we ended up chatting on msn and working on projects together. I couldn't tell you any users on my instance or elsewhere other than the admins of my instance.
I just used Virtualbox's auto install feature yesterday and it was insane. Literally just put in name and password and iso and it did the rest.