"While I understand the "Heller" decision and all that, the constitution was framed in a different time. Firearms, and the best, were absolutely necessary then. The same is not so true today. Plus, it is accepted that the 2nd Amendment is subject to reasonable restrictions. We already cannot buy mortars, machine-guns and cruise missiles, for the public good. If, something less-lethal but more effective came along for self defense, wouldn't it be better for society to embrace it and pass semi-automatic firearms into realm of military-only use?"
The two things that come to mind deal with disparity of force and intent. On one hand you posit that non lethal force should be sufficient to prevent being killed by attackers who may be armed with lethal devices of their choice and who also may be in a group of 3 or more who are INTENT ON KILLING YOU while you are only concerned with stopping the attack. Disparity of force.
I am curious as to why you would relegate semiauto firearms to "military-only use" if they are no longer needed for self protection and are capable of subduing evil doers non lethally? Is it because the military and LEOs must deal with numerous murderous violent attackers armed with lethal devices themselves? I submit that I must be as well equipped as possible to protect myself against violent attackers equally well.
Our esteemed VP says "buy a shotgun". He is of the impression that the sound of a shotgun "blast" will cause an intruder to run. Why not just get a recording of an 870 12 ga slide being racked and then the sound of a shotgun "blast"? Foolish eh? Actually, he is partially correct in that the sound of a shotgun being actually fired AT an intruder with the smoke and 00 buck entering just 1 attacker will probably be enough to end the attack and send the others packing. Your taser will not really cause additional attackers to run, they will just tackle you and beat you to death, or stab you to death, or possibly use a lethal weapon like a HiPoint semiauto to shoot you. Meanwhile, your battery is dead and so are you.