First, let me say that I haven't read the entire thread. I've only read the OP so, if these ideas have already been put forth, bravo to the poster(s) who offered them.
There is NO reason to keep any costume parts behind a grind target, or have them used as the "prize" for any given accomplishment. That's what badges are for.
If I have a level 50 toon on one server, and want to enter a costume contest on another server, I want the option of making a new character with the same, or similar name, rather than having to transfer the level 50 character to the contest server and lose whatever is in vault storage, SG membership, and server contact list to show off or for a chance at winning some prize at the whim of another player or players, or staff member(s), for that matter. I don't want costume options for the newly made copy to be level/accomplishment locked because I didn't play on that particular server. The only way that a costume contest can be considered even remotely fair is if all contestants have access to the same materials to construct their costumes with.
Again, if you feel the need to show off accomplishments to be able to enjoy the game, which is all very well and good for YOU, do whatever is required in order to win the badge. Don't try to restrict the enjoyment of others who have every right to play the game the way they want to for their entertainment.