School/Work Build need advice on components?

That is not what Active PFC means, its a feature that automatically adapts to the power coming from the wall. You'l notice on old supply's that there's a switch between 220 and 115v, that's telling the PSU what to expect to come from the wall. Which one you should have set it too depends on where you live.
Active PFC just means that you don't have to set it manually, will figure it out on its own and adapt accordingly.

Consider Active PFC and 80+ Certification as your baseline for picking a PSU, anything that doesn't have either is not worth considering (except the Antec VP-550, but that's the exception).

Why bother with a graphics card at all?
The 3770k has more than enough grunt to throw at what the OP's doing, and has HD4000 which is sufficient for his needs.

The build you specced out will be fine IMO for what your doing, though I see storage becoming a problem with it. Might wanna throw a 1TB HDD in it.

Questions.
1. Nope, 4.2Ghz is a fairly easy overclock.
2. My opinion is you dont, HD4000 will cover your for what your after
3. Something from Seasonic, Corsair or XFX. Since you have no GPU, a 400W would be sufficient. But if you want to leave yourself the option of getting one later, a 550W would be better.

Also, getting a Define R4 with window kind of defeats the point. Thing is covered in sound damping foam, only to be betrayed by a large acrylic window for sound to leak out of.