ok... first up do you have to set the open tuning to the key you want to play in?
or can you play say slide in open g to a song in b?
second question, possibly even dumber than number one is how do you find the key of something you played in slide/open tuning?
thats it.

i think. your help would be much apreciated
just because you feel it dosnt mean its there
if you're using an open tuning you can easily just use a capo to put in the key you want

you also, don't have to play slide in an open tuning (it usually is much easier though)