If I understand correctly, you're looking for algs to pair all of the last layer edges. In K4 this is done with commutators. I can understand some of the simpler ones like (r R U R' U' r' U R U' R') and it's mirrors, but I'm sure there's a sheet with a lot more cases you can look at somewhere...
Better is pretty subjective in this case. Both methods are good and it just depends on which you're most comfortable with. I use Hoya and would argue that it's better for me. Lookahead on cross edges is much easier for me with Hoya and also transitioning between steps flows much nicer. I think...
I recommend learning COLL. Even if you don't end up using much of it, it can help with PLL prediction. Also, it's an essential precursor to learning any ZBLL
I distinctly remember a point when Kevin Hays said he was retiring from cubing. However, when I look at his WCA profile, I have no idea when that would have been. It must be a Mandela effect. By the way does anyone remember a cube company called GANS?
I don't think age is as much of an issue as many people make it out to be. I started in my 30's and I'm sub-15 now at 43. The time you have, as you stated, is definitely a big factor though. I go through long times of minimal practice due to my other obligations in life, but lately it's all I do...
CLL isn't bad but ELL recognition sucks. It's worth learning some of the easy to recognize cases to use when they pop up but I'd rather use OLL/PLL just cause the recognition is easier.
I know everyone hates on Hoya, but still I'd recommend trying it out for 4x4 and 5x5. I personally dropped my times pretty rapidly after switching from Yau when I was averaging about 1:30 on 4x4
First comp in 4 years today. I got a pb Ao12 while practicing at the venue (12.983). Managed to get sub-15 average on first round (14.732) despite 2 16.xy solves.
Update: the rest of my stuff didn’t go too well but someone got NAR single (3.8x)