I think the quick travel cost would work better if it targeted richer players, I don't think F2P or preferred should be forced to have a fee when their credits are already so limited.
I suggest raising the credit cap and the GTN credit cap so that you can extract more credits from the GTN tax, then creating craftable, bind on use mounts, weapons and armor, that require expensive materials to incentivize bigger sums to be traded on the GTN.
Making the Appearance Designer cost credits, depending on how much you charge this can extract a lot from the players.
Lastly, having a flair that upgrades in appearance the more you spend with a leaderboard showing who has spent the most.