theres like thousands of tags so i doubt there’s a comprehensive list, because people can tag their works however they want and new tags are always being added. honestly, it’s easier to sort by pairing/ship or by fandom, and then go to the sidebar (filters) and apply what filters you want. my go-to is sorting by kudos (which will put fics with most kudos first. this is a good way to find well-liked and popular works), and then i usually filter out some archive warnings such as underage. i also
(2) always do complete works only, but this is just my personal preference. i’ve been burned too many times by fics that never get updated and end on a cliffhanger. and then instead of filtering tags, just look at the individual tags on a work, which will tell you what’s in the fic. if there’s any specifics you need explained, im kind of an ao3 expert so i could help