Open problems

These problems are mostly original, and (of course) reflect my personal taste. But I have tried to sample different topics.

I categorize problems on a conceptual-technical spectrum. That is

Of course these overlap. Continuize by taking "type 2" in the middle of an inteval 1.5 - 2.5. Then we can order the problems across this spectrum.

In a different realm, I really really really want someone to do this simulation. Of course, it's not easy!