As stated by another person, yeah I'd want it to not overlap with the existing ICANN TLDs. Not too hard to do, and we could fix one of the bigger annoyances of DNS and correct the ordering: bsnes.byuu.org -> #newtld.byuu.bsnes, for example could work, or even just #byuu -> #byuu.bsnes and only have a sole TLD for it.

I don't know how we stop squatters, maybe a one-time registration fee would be reasonable, but that would be discriminatory as $100 would be trivial for developers in the US, and impossible for service workers in Mozambique that just want a personal website.

It's not as though .com/.net/.org (and heck, even a lot of the new gTLDs) aren't absolutely filled to the brim with squatters already.