In an entirely different question, I know you need to beat the Elite Four, get the National Dex, and get the Ruby and Sapphire key items in order to trade outside of FRLG in those games. However, does that only prevent trading between non-Kanto Dex Pokemon, or trading with RSE entirely? I want to trade a TM from my non-completed Leaf Green over to Emerald and I want to know if I need to take a detour between my completed Fire Red first. (Gen V TM System, why you no introduced earlier. ;__;)
FYI, you also need to have beaten the E4 in Emerald to unlock trades with Kanto games.