Thanks for these, Jolan. Rushed today, but an unqualified delight as usual.
Here is my stab at them.
1. A sound step dancer (7) – ASTAIRE? (Sounds like a step - a stair- Fred Astaire was a dancer)
2. Risk all on one play or film with everything going (5,3,5)- SHOOT THE WORKS (Film – shoot , “everything going” – the works. This gives “shoot the works" which means “Risk all on one play”.)
3. Drug preparation to help suffocating pet has no lasting effect (3,2)- HOP UP? (Subtractive anagram with “preparation to” the anagrind. “help suffocating pet” without “lasting effect” gives “hop up” – to drug)
4. Nozzles for a blast of air are precious to the Royal Society (6)- TWEERS? (Precious – twee, with RS – Royal Society, gives tweers, nozzles in furnaces for blasts of air)
5. Muhammad Ali supports faults of character not apparent at first (4,2,4)- FEET OF CLAY? (Muhammad Ali was originally known as Cassius Clay. His "supports" would thus be “feet of Clay”, - “faults of character not apparent at first”)
Thanks again.
AB
PS- Welcome back Aristo. Search parties were being organised.