Ok, so we're getting ready to file to lift conditions for Terry's permanent residency. If we have everything else including birth certificates for all three of our children, adoption decrees for the older two, our mortgage, tax returns, joint bank account info, joint utility info, etc...do we really NEED the affidavits or is that more if you're lacking in the other stuff?

They're not necessary -- particularly where you have children. Birth certificates are the ultimate I-751 evidence. Those and the mortgage (throw in the deed) and joint financial info should be more than sufficient.

Sounds like you have a LOT of power!
I still believe in the" more ammo the better" tho.

Honestly, I'm a little concerned that they might look at the three kids and be like, "Uhhh...adopted two and one biological? Trying a little too hard, aren't we?"