Yeah, it can be a pain to get all those abilities (especially since you essentially need to have a Nu Mou with all the Beastmaster abilities), but I'd say it's worth it. I still have yet to find any instruments that teach Sprite or Dragon Beast Lores, since those are the only monsters I have left that have most of the Blue Magics I need, although I'd guess the auctions would be my best bet.

Still don't have those Ninja Tabi, although I was able to find Faerie Shoes in a treasure urn. I gave them to my Luso who's also a Ranger. I love using Focus-> Sidewinder to utterly destroy any monster enemies. I got a Rangetsu-denbu from the auction house, I gave it to my Adelle so she could assassinate things (giving her the faerie shoes if I'm not using Luso). I'd like to get more, because if it's the same as FFTA, you learn the ability faster if you have two of the same equipments that teach the same ability.

For whatever reason, I always end up finding a random clan entry character on the months when Nu Mou always appear. I think it's a sign that I should try out that Magick Frenzy thing, so I've begun raising them as Illusionists.