Just unlocked my first covenant renown 80, should I switch to farm another one?

Just did the night fae grind, renown 80, night fae campaign halfway done, chains of domination quest line not done, zereth Mortis partially unlocked (no world quests).

Should I complete my night fae campaign, switch covenant, buy renown 60 skip and then continue other major quest lines, to maximize renown gains?

Also, how come anima bank can hold up to 200'000 anima, but you earn a kiddie's diddly from quests? Does all of the substantial gain of anima come from zereth mortis?

How much anima in total you need for 1 covenant and total?