I'm going to guess that you're talking about Stephen Lester in your first point. Or maybe it's someone even older like Valentin Vornicu. But slester joined in 2015 which was way after the community was made so it might be Valentin Vornicu you're talking about...

I feel like people are just inconsiderate to how much work people who work for AoPS have to do to keep things running smoothly (made even more difficult during this challenging time) so they just liberally ask for "improvements" when they feel that they need something to be a tiny bit more convenient, and some people dont even pause to look at the full scope of their change and fail to see what could be wrong with it.
For example, many people ask for forum managers to have different powers to "help manage their forum" but much of that can be solved if the owner chose a few responsible people to take care of the forum. then there wouldnt be a problem. The global forms run perfectly fine because there are a few responsible people in charge of it, as well as established rules and etiquette . Unfortunately many forum owners are unable to follow that model and therefore have so many problems with managing their forum. The current powers that forum managers have are simple to understand and work well if people know how to use them.

That explains a lot. I've been wondering why!

Did Mr. Rusczyk develop the community? I think he told us once in a video...

I used to be one of those people who would suggest things (legitimately wanting to help) but now I don't suggest much anymore. A lot of the common issues people have with the forum system can be solved with userscripts, and the rest are probably too large to be implemented.

Ok, I think I got it. Is it paulhryu??? Also didn't Vornicu have to have something to do with the community since he was the only creator of MathLinks?

Actually let me rethink that, the community had to have been developed before you joined in 2007 and before Paul joined in 2009 (unless, of course you're talking about the 2015- community, in which case I think it's Paul like I said before). But anyway, in those days it was richard, valentin, crawford, and dave, and maybe other people i dont know about. Out of those people I would have guessed vornicu but you have already said that that was not correct, so I think it's Richard. Judging by early site support questions, he answered the second most questions (behind valentin).

So my final guesses are Paul H. Ryu and Richard Rusczyk

I'm not sure I'm allowed to say. It was written circa 2013-2015.