Toad, Korean Boeing was a valid target. If it was a 747 and not RC-135.
Soviet pilot couldn't hesitate: the invader crossed several hundreed kilometers of Soviet land, including the key defence structures of the Far East. He was protecting his land, and he in no way was a coward shooting down an airliner because he crapped his pants afraid of possible attack on a ship half a world away from his country.
Yor version that Soviet interceptor didn't contact KAL007 on "international radio frequency" can be only interpreted as "he failed to get in gontact - Koreans (if they were Koreans) didn't answer". He unloaded his cannon ammo to attrackt their attention.
In late-70s another KAL plane "mixed up" East and West directions, and landed on a frozen lake in the North. When possible - they are landed. When not - sorry.
I want to point at the grade of moral corruption of the regime that sends civilian airliners as target-drones for air defence. It is something unthinkable.
Toad, MAD became possible only in early-80s. US had B-52s on 24/7 "combat patrol" until 70s. They were ready to penetrate into Soviet airspace on routes discovered by your "peacefull missions" with one goal: to burn millions, millions of people, who's only fault was being Russian, Ukrainian,. Tatar - Soviet.
Go find something about "Drop Shot" attack plan. It openly stated that USSR doesn't plan aggression against US or Europe, and the war is "preventive". According to that plan - 8 million Soviet citizens were supposed to be killed in first 30 days. US deliberately have chosen genocide as an instrument of military and political struggle. Anyway, according to Drop Shot estimations - Soviet Army could occupy Europe and gain access to Indian Ocean in no more then 6 months. American airforce main bases in UK were estimated to survive for no more then 60 days before being wiped out by Soviet nuclear weapons. All this only as a result of American "preventive" first strike against USSR.
Your politicians always understood that USSR wants to be left alone, and will never start a global war because of intentions to "enslave" othr nations. Anyway - they planned nuclear genocide of Soviet people. They relied on genocide, because American nukes couldn't make any significant damage to Soviet Army. And they knew that USSR can't be defeated by the power of weapons, so they simply decided to wipe out Soviet cities to make us surrender to the aggression.
Face it, mr. "dove of peace". You were searching for weak spots for US nuclear bombers to slaughter millions of innocent people. Think of it before you go to bed.