In writing any post, a popup comes up showing a list of current matches. But take a leaf out of Stack exchange and PUT IT ABOVE THE COMMENT BOX AND NOT ON TOP OF IT. You can put a check box there if you want people to look at the list first.
Worse, it’s persistent. I hit esc to kill it and it comes back like a ‘brother are you saved’ street preacher.
Second issue: If you limit how many posts I can start on my first day, tell me before I write it. e.g. with my Nth post tell me. “Dart, you’ve done enough. You can rest now” before I write the N+1th
You may want to add a forum category for forum user interface.
I can only do so much with it, mostly in relation to the theme or sometimes if there is an extension that might do what someone wants, I can look into it. I can also change settings. Looking that one up, I do think 3 for the first day may be a little low. Do note that only counts for new threads though, searching for existing discussions and adding to them is not counted in that.
Changing fundamental behaviour—like how the help tool works when composing, or whether to warn about this or that, now or later—is under the domain of those that make the software. I agree with both of your points there though.