One thing that really helps with missiles is reducing their clustering values in the CombatGameConstants.json, found under BATTLETECH/Battletech_Data/StreamingAssets/data/constants.
"ClusterChanceOriginalLocationMultiplier": 8, -> adjust to 4
"ClusterChanceAdjacentMultiplier": 4, -> adjust to 2
"ClusterChanceNonadjacentMultiplier": 1,
This makes the missiles behave a lot more like we are used to from CBT, clustering all over the target instead of behaving more like "Follow the Leader" special ammunition and drilling through one section and it's adjacent ones.
Adjusting the missile weapons stability damage will also help greatly, even a slight reduction makes AC's noticeably better at inflicting stability damage. Their values are in the same path as above, just in the "/weapon" folder instead of the "/constants" folder.
There's also another variable I would definately change if you do this however!
"UnsteadyCountersGuarded" - this is set to false by default... it would just be overpowered with the vanilla stability damage inflicted by missiles. I would set it to true if you use the reduced clustering settings and reduce stability damage of missiles.
FYI, there are a lot more settings that can hugely affect the way the game plays, besides just the sensor and view ranges. There are variables for "SolidBlow" "NormalBlow and "GlancingBlow", which all have their own damage multiplier and can be set to counter guarded as well. This is potentially a tool to make Assault and Heavy Mechs less powerful compared to Mediums and Lights, since one good high damage salvo could strip the guarded status, which the Bulwark trait automatically applies if a Mech with such a pilot does not move(except for facing changes).
Regarding the problems ArkRoyalRavager has with the refire modifier that autocannons get, consider not firing them more than a few rounds in a row and insted jump+brace or sprint to a better position. Not only will you force the AI to react to a sudden threat in its flank(which it does, usually by pulling back the most damaged Mech's), you also get potential side shots which make it much easier to drill through a Mechs armor to the CT, since you can't hit the opposite side torso or arm from a side firing position. This goes especially for the AC20, since it gets the highest refire debuff. A pilot with high guts(like the starter Mechwarrior Behemoth) also helps tremendously with this penality... and if paired with the "evasive movement" skill and high piloting(which extends your sprint distance), offers another option... just going into melee, or sprinting into a position that threatens a melee attack next turn. The refire modifier resets after not firing the AC for one round.
Beware though... any patch will likely overwrite your changes, so you may want to save the changed files somewhere else for backup, or you will have to do this all over again if a major patch comes in or you have to repair the installation for some reason.
