AngelScript isn't that difficult, really. There's an extensive manual for it and you can look at existing levels to try and figure out how stuff works. Sure, there's a bit of a learning curve, but once you learn how to use it you can do a lot of cool stuff, including implementation of the ideas you've described in this thread.

I understand the sentiment of "I don't know how to program, so what is JJ2+ doing for me?". But on the other hand, the JJ2+ team only has limited time and motivation. Spending it on features that allow other people to implement whatever game mode or game feature they have in mind is in my opinion the best way to go, rather than (for example) focusing on adding a few specific game modes which would mean other features would never get added at all.