Changing Grand Companies

[MaethusXion]

But if you're rank is 2nd Lt. In Adders, and switch companies, you still keep that rank, right?

If you switch GCs you lose access to your old GC's Seals, Equipment, and Rank. A 2ndLT Maelstrom will lose access to all PvP ranks, Storm Seals, Maelstrom Equipment/Barding, but still actually retain the rank and Storm Seals in a "hidden" section that you can't access unless you switch back to the Maelstrom.