Mike Smith wrote:
2) About spins: I am new at flying a 172. 25 hours. Owned two Pitts
Specials but never a 172. Only have 25 hours in a 172... My question:
In a 172, can a spin be accelerated (made to spin faster) by a)
starting the spin with full rudder and full back stick elevator and
then b) once the spin gets going, then moving the stick to half back,
not full back? Anybody tried it in a 172? Any problems? Just
curious.

NASA has some good video of the tests they did in the 1980's.
Certification only requires two turns.
NASA had to use their spin chute for recovery on at least one occasion
as I recall.