This is ready to install, no drilling or tapping required.
Yes, the JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight will be compatible with a Ballistic Advantage Hansen Barrel as they use a 0.750" gas journal diameter, which will allow this gas block to fit properly.
The JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight should work fine with that handguard.
This P Enterprises .750 Adjustable Gas System and A2-Type Clamp-On Sight uses an easy to access side gas adjustment. Adjustment: 8-32 x 1/4" stainless set screw, 5/64 hex drive (hex key included).
Yes, the JP Enterprises .750 Adjustable Gas System is compatible with your Bushmaster AR15.
The JP Enterprises .750 Adjustable Gas System and A2-Type Clamp-On Sight will work with Magpul SE handguards as long as you have a delta ring and handguard cap to install the handguard.
The JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight can be used with a 5.56/.223 barrel as long as the gas block journal is .750".
The JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight has a length of 1.87". The Faxon 7.62x39 Gunner Barrel has a gas block journal length of 1.9". So it will work with that barrel.
The JP Enterprises .750 Adjustable Gas System And A2-Type Clamp-On Sight should work for a Smith and Wesson M&P10. From what information I could find that rifle uses a .750 gas block.
Your barrel will have to be .750" in Diameter for this to work.