Moss Doesn't help your Windurst fame.
For windy fame, go to bastok markets and Find the Vendor that sells Coronets. 230~ each. Buy as many as you can hold.
Trade them to a NPC in windy Walls for a Quet, something to do with Mandragoras. you get 200 for each of em. After about 300 Coronets, you should have max windy fame if you started from fresh. You will spend 1000 gil on coronets over all, and about 5k-10k on transpertation if you don't have the outpost teleports.
It shoud take 2-3 hours.
And yes, you have to have a moon bauble in order to get fenrir.
Primes are pansys. I've seen several people Duo them on multiple occasions.
It can be done as (any Damage Dealer with both Utsusemis) and a whm, or it can be done as Rdm and Bard, or Rdm can solo, or Monk/war can almost solo, take a whm just in case for that one tho.