You might get more in depth answers if you don't post so many various questions all together in a lump.
I'll take one:
What is toe overlap?
Sometimes also called toe clip overlap (wearing clips make the problem worse), here's what Sheldon Brown had to say about it:

Toe Clip Overlap
On many bicycles, especially smaller sizes, it is possible for the front fender or tire to bump into the rider's toe or to the toe clip. Some people worry a lot about this, but it is rarely a significant problem in practice.
The only time it can happen is when the handlebars are turned quite far to the side, which only happens at very low speeds.
Many, many people ride bikes with fairly severe overlap with no practical problems, sometimes having to make a slight adjustment to their pedaling habits at very slow speeds.
On smaller size bikes with full size wheels, it is usually impossible to eliminate overlap without causing adverse fit/handling issues.