First of all, steam will not be nessicary to run the game, so you don't have to register it on steam if you don't want to. Secondly, if you do register it on steam, you can just Rebind the key to open RTB in Options -> Controls, mine is set to Left alt, so this isn't a problem for me at all.
Overall, this isn't an issue, and doesn't deserve a help topic because it is easy to remedy.
tl;dr= Rebind the "open RTB" key in Options ->Controls