I am not sure if they already have something like this, but if not they should. I find that, gaining reputation for places can take a bit long. Now I realize that you can do quests for that group (for example , The Men Of Bree) and you are awarded with about +700-1600 rep. points, but i just think to speed the process up a bit Turbine should make reputation tabards.
Here is how it would work: when you equip the tabard that represents the group that you want to increase your reputation with, (possibly to your Cosmetics) your reputation with that group would increase every time you kill a monster in a instance. However, to insure that reputation would not increase too fast, you would only gain about 10-20 Reputation points each kill.
Boosters are always nice, but your system sounds slightly complicated to me.
Alas, Turbine offers reputatio accelerators in the skirmsih camp and in the store; it is doubtful they will add more work into this when it effectively allows people to gain reputation and TP through that faster.
They have reputation tabards already. You get them in Goblin-town. They give you Rivendell rep
Is this a WoW-born idea? It definitely woudlnt work in LOTRO.
For one, it'd make it way too easy to farm rep for TP. Create a new alt. Send them a Rep Tabard for every faction. Farm animals in Ered Luin in a group with other farmers. Gain 50 TP for every faction before you even reach Noglond.
Second, it doesnt even make sense. Why would the Malledhrim care if you're killing Brigands in the Shire, just because you're wearing their colors? You gain rep with them by doing things that actually help them, namely quests and giving them things they need/bounties on their enemies (task items).