I personally believe that:
--You should be able to use deadly force on anyone who attacks you, poses any physical threat to you or those around you, or breaks into owned or rented land or housing of yours with intent or reasonable possibility of intent to commit crimes the persons or property of any occupants of the land or home. There are no exceptions and no "duty to retreat" clause.
--ou should be able to use non-lethal force (pepper spray, physical restraint, etc.) against those actually in the process of commiting a nonviolent crime against you or your property. Again, no exceptions.
--Certain types of small, compact automatic SMGs (HK MP7, Steyr TMP), etc should be legalized as self-defense weapons. There would be stricter gun-control laws for these weapons than for other firearms.