how do you get it to update to betas and gm's instead of having to restore?
You have too restore so just backup and sync so your phone stays the same. Also make sure it's a GM because if it's just a beta you will need your device registered to a dev account to activate.
nah its a gm i got it directly from apple
sucks because its taking forever to install all my apps, official version will i have to restore again?
Not until 4.2.1 or whatever comes out next. I don't think it will do it automatically. You will just have too restore to get it back to auto updates.