I just cleaned my TB today .. how bad is it to overtighten these bolts?

I normally follow the tightening order like below for most parts but it was late and my back was killing me from leaning over.

Should I unbolt and tighten to spec? Will I need a new gasket if I do that?

 

Should have replaced your ERG valve while you had the thing off. It's a common failure on Maximas.

I would loosen the bolts and tighten them to torque spec. You won't damage the bolts (unless you over-tightened them to death), but because of heat expansion you can wear out your gasket prematurely. Get a long socket extension, it makes life a lot easier under the hood

Also, you should be ok if you put a new gasket on when you put it back together, so no need to replace it.

 

No reason to replace the EGR valve if it hasn't yet failed, and it's not that common. Not common enough to warrant replacing a currently functioning part, anyway, unlike the coils on a '99 or similar.

OP: The exact proper torque spec and sequence for the TB bolts doesn't really matter, honestly. As long as they're tight/snug, it'll be fine.