I know @zef is busy with a lot of things, so this is an open question to the community: if someone could give me pointers on how to either solve these bugs, or to make it easier for @zef or others to solve, I'd most appreciate it!
In general, if somebody is an invested user of vim mode (I'm not using it myself, right now) I'd love an "owner" of this dimension of SilverBullet. Likely these issues keep deprioritized (until I have a "Vim moment" again ).
I'm happy to be that person informally. I can help prioritize and curate the vim work that needs to be done, and with a bit of pointers/guidance, should be able to start contributing code and fixes as well. The major caveat is I currently will work in bursts and spurts just because of other things in life.
One thing to note though: the above all seem to be folding related, not vim related. The second one is arguably vim related, but let me check if it occurs in emacs mode as well.