Background Intelligent Transfer Service is required for Windows Updates to function properly.
It is safe to set this to Manual.
If you want to continue using Windows Update you must not disable this service.
Game Booster disables some services based on the theory that it will free up the system to 'concentrate' more on the Game itself.
I have found no evidence that Game Booster actually helps anything; I don't believe it actually hurts anything, either.
Just be sure to turn it off when you're done with it.
As with all Services manipulation, my best advice is, if you are unsure, leave it alone. That is, leave it set to its default setting.
A complete guide to Windows Services can be found at: Black Viper's Web Site
Don't let the name throw you off; I think he's quite good.
Hope this helps!