1. No need to go and retorque. Like I said, Mount it and forget it.
2. A little more security can't be a bad thing.
3. How long does it take to apply that drop? Not more than a second.

FWIW, allot of the newer UAVs are using Safetywire on the prop bolts. No need for locktite when using safety wire To be honest this is a method I would probably consider on larger engines.

Basically, you do what you think you need to do and I will do my method. They both seem to work just fine.