If you leave the one bolt in, you'll have to remove the air filter cover. It's probably slightly easier just to pull all three of the bolts out to replace VVT sensor. If I remember right it was still pretty tight in there without pulling that last bolt from the power steering pump.
You're not going to want to bump that connector at the top of the VVT at all, while trying to squeeze in between the pump and the side of the engine. You could cause early wear/damage and that's where the oil starts to leak from when they start to go bad.