too bad, u can't do besaid or macalania without fiting valefor n shiva.

no u cant get anima
no u cant get yuna's sigil
yes u can get yunas crest. go to besaid beach and go in the water, then swim rite to find an alcov with the moon crest in it. granted its pretty useless on its own
yes u can get magus sisters, u only need to defeat belgemine's bahamut to get the key item required for the magus sisters. u will laso need to catch one of every fiend on gagazet for the 2nd key item