Thank you for your feedback!
Notifications are indeed on my to do list. As well as a more accessible RST reference, right when you're replying/creating a new thread. The RST syntax on the forum supports the GitHub-flavored ```lang ... ``` code blocks, and many people don't realise that.
Your other points are also valid.
But now let me give you the Nim communities perspective. Why did we decide to write our own forum? Well, for three reasons:
1. The old forum used phpBB which is horrible. When the Nim forum was initially written, the "nice" forum software didn't exist (Discourse).
2. (Kind of a continuation of 1) popular forum software was always spammed to death by bots, because of the software's popularity those bots were far more prevalent. It was our belief that a custom forum would have a lower chance of getting spam, and we are mostly right about that.
3. We want to test Nim. The amount of bugs that the development of the Nim Forum (as well as Jester which the forum uses) uncovered is phenomenal. The Nim forum is also a showcase of what Nim can do, and I think that's important.
What I find puzzling though, is the fact that many of your points could also be said about Hacker News. Hacker News has no notifications, no friendly GitHub-flavored Markdown syntax and also has awkward little buttons (the upvote/downvote on mobile is irritating). Yet it thrives and you yourself use it.