Yes, it should be compatible with 3-position binary triggers.
The Combat model is a short throw safety selector.
Yes, it should.
This weighs 1.6oz.
An authentic Colt 9mm AR is built on a standard AR-15 receiver with a mag insert, so yes.
The answer is a qualified yes for other clones. Most 9mm specific lower receivers use standard AR-15 parts but you'd have to check your specific manufacturer.
No, the models these will fit are AR-15, AR-10, M-16 & M-4 firearms.