Technically, the FAA can count as commercial flying any flying which requires a commercial certificate, which includes CFI work whether paid or not.

They could even bust you for teaching a family member to fly on weekends and not counting it against 121 limits. The reality is that they don't seem to care about "friends-and-family" non-paid instruction.

But I think they would nail you for the ground school scheme...it's based on the character of the flying, not whether any money or other compensation changed hands.