A lot of the suggestions I've seen are fixes for relatively minor issues, but the major ones and the ones I wish he'd really consider have to do with the shitposting situation. I agree with him that even small changes can have huge (and probably unintended/unexpected) effects, but things like adding more moderators ought to be a no-brainer. Things like adding a merit requirement to rank up to Jr. Member would at least be a good experiment to see what happens, and it isn't like that kind of decision would have to be set in stone. Hell, Theymos could do away with the merit system if he thought it wasn't working and there would be nothing any of us could do about it. There would be no shame in doing so, either.
Removing signatures from Newbies/Juniors is essential in my opinion. It effects their ability to post here zero, just earn, but someone who can't speak English very well and has little to no interest or understanding of bitcoin shouldn't be able to get paid to post here and it's crazy that they can. Requiring users to get ten merit and become a Member can be some sort of aptitude test for them and once they pass it by getting the merit then they can start earning via posting. Newbies and Juniors barely have a signature anyway so it's not a huge issue to remove it completely anyway.
And yet it seems like most of the community suggestions aren't priority for him. His priority is apparently starting up a youtube channel for whatever reason. I don't actually think that's a horrible idea, but it just shows you how different he views the state of this forum. There are a number of members here who would probably suggest that he try to fix some of the glaring issues with his limited time instead of doing the youtube thing.
A youtube channel should be very low down on the list of priorities right now, especially if it's going to consume more of his free time which is already obviously limited. If he's going to delegate this to someone else then fair enough, but then there are also a lot of other things that can be delegated that you and I have mentioned numerous times before.