Time signatures have nothing to do with feel. All time signatures do is give you a place to start in terms of reading. Time signatures and tempo markings are two different entities. Feel is another separate entity. Straight eights and swing eights are written exactly the same. The straight eights are read as triplets in swing and a good deal of bebop. Straight eights make the reading easier.

"If everything is one, how do you know which time signature to write in??"

It's either 3 or 4 in some form, most of the time. If you want to accent the next beat, have at it. What difference does it make where you start? 3 is three and 4 is four. Variations only occur to make the music more complicated.
This is simply a math question. The various ways that people view math will control how it's written on paper.
Playing and reading/writing are two different items. Reading/writing takes tons of practise and experience.

"Some drum parts will reach up to 64th notes, and have 12-16 hits per beat."

Granted. But I haven't met the person that could count out loud 12 or 16 taps at tempo marking of 120 or 100, for that matter.

I'll give powertab a gander, but I sincerely doubt, it does what I am saying. For example:

/ / / /|
1 a seven note figure (evenly)
2 a duple
3 a triplet
4 2 eigth notes
These are beat 1 thru 4.

Again, time signatures only give one a place to start. X=X.