Another thing to maybe think about is a clear separation between the commercial activities of the club/school/CFI/whatever, and the not-for-profit activities.
Even in a non-for-profit club, the CFI (and maybe other instructors as well) do this for a living and to be honest, you can't fault them for that. So if you arrange one-on-one instruction, either on the ground or in the air, they're being paid for that. Simple. And if they're propping up the bar and you ask them a simple question, they don't expect payment, other than maybe another beer if the answer is mouth-drying long. But what about the activities in between? If the CFI organizes one of those Friday-afternoon flyouts and he flies one leg as a passenger in the RHS and dispenses some good advice from there?
Another example: we have occasions where we have instructors with us as safety pilots even though we as PPLs execute the flight as PIC. Spot landing practice/competitions for instance. In this particular case, my club makes clear that the entry fee into the activity also covers instructor payment for the day. That makes it clear what to expect.