You can indeed do that, but there is a platinum cap on any account unless they have 1500 loyalty points (requiring a purchase whether through play by REX or by spending creds). The cap is 2500 platinum, but I believe you also need level 50 to have the 2500 platinum cap, and the max plat you have scales based on your level. I.e. Lower level, the cap is lower, until level 50 where you reach the plat cap. Yes, you can make an account on any US server, and transfer it to a different US Server for free. You can not transfer it to an EU server though, and simply making a level 1 mule for transferring purposes won't work either, due to the platinum cap restraints at level 1.
On another note, I don't know why I'm still in these forums after I quit Rift, but I might have some spare plat to sell if you are on Laethys
.