That’s a lot of words to say you want a particular feature in Mechwarrior which almost nobody else really wants.
I’m not even wildly opposed to cone of fire weapons that would kick in while moving and get worse the faster you move … except that it simply is not an important thing and adds rng that most people will just find frustrating and honestly would probably encourage less mobile gameplay.
For single player being able to kill mechs efficiently is kinda the point of the game; each mission is a series of fights you are trying to get through without using up too many resources. Should you be able to easily headshot mechs? Probably not and that I am sure will be fixed. Should you be able to kill an Atlas by taking out only 20% of its armour? Yes. Better players will do it well and worse players will struggle and hopefully they will be able to dial up the AI difficulty to challenge the better players. taking away weapon accuracy is just unnecessary sandbagging that will hurt worse players worse than it will hurt good players anyway.
Remember when they added weapon accuracy while jumpjets were firing in MWO (a necessary and good change for various reasons imho), one of the effects was that it pushed jumpsniping out of the reach of the average player.