OK, poll closed yesterday. Sorry I didn't get to discussing it further then, but I wasn't feeling great yesterday.
The Winners
Feats at 1st level
Feat schedule depends on your class rather than at a set level like in 5e
Feats have class/level prereqs
No half-feats.
20 levels
From The Comments
There were some interesting comments about having the game be open-ended in terms of levels, along with the idea that each level costs a very predictable amount of XP--1,000 points, or 1,000 x the level to be obtained. There were also ideas about front-loading the abilities, so after a while, what you get primarily when you go up in level are more feats. That would certainly make it far easier to have infinite levels.
There was some contention between people who wanted feats as a separate thing and those who didn't but wanted each level to have a choice of powers, so that not all characters of the same class and level were the same. I think the two can be easily combined: Feats every X levels (depending on class) and class choices on other levels--at least until you reach that point where you stop getting class abilities and only get feats.
The Current State of the Polls can be found here.
So unless there are any other ideas, I will work on a poll for Fighters.