COLL is worth it, there are only a few cases that are really bad and are probably best ignored, like diag T, which is the only COLL I never use in solves. I'd be happy to PM you my algs if you want em.
OLLCP might be worth it, I'm still not sure if I'd be faster if I never paid attention and just went straight into OLL without bothering to pause and check the CP, sometimes just to get a Z perm instead of J. :CC
Of course go for easy xcrosses and 2x2x2/3 blocks.
I wouldn't bother with 1LLL like ZZ/ZBLL, or complex, high alg-count LS methods, other than a few easy to recognize cases here and there. For instance, I know a few 2GLLs for T/U when there is a solved 1x2x3 block, making it super easy to recognize. Also, they're mostly just sune combos.
Spending too much extra recognition time on solving EO during F2L probably isn't worth it unless you're super good at COLL or know a lot of ZBLL since so many OLLs are just as fast, or faster than OCLLs.
Also, practice diagonal PLLs until you're fingers bleed, they come up, it's best just to deal with them. I used to hate hate hate E perm. Then I practiced the RUD alg for weeks. Now it's my favorite diag, the only one I can sub1. Same with Na perm, used to hate it, practiced the RUD alg and got better. It still isn't great, but it's not as damning to a solve as it was before. Nb can go **** itself. V is k.