Who lets himself be reliably hit by someone with a TAG at 1000+m?
Narc could probably be awesome if they ditched the damage threshold. Latch it on, have it last a minute or so, and Scouts and LRM users might love Narc.
Of cours, spotting might also work better if missiles where much faster. They wouldn't look as neat, but damn it, but if a scout only has to lock on for 0.5 to 1 second and those missiles would hit, then things would get interesting. If LRMs turned to powerful then, just lower their damage.
You mention some points that serve to balance out/ justify the increased range for tag.
I do think missile speed needs to be increased but the way they hit needs to be reworked. i favor using the SSRM system for groups of 5 and RNG the Hit locations. same for SRM's but per missile. interesting that the SSRM hit allocation system is basically a RNG from TT.
LRM range really needs to be boosted to 2000m since all other weapons where given damage drop off over vastly greater ranges from TT. LRM's need that love as well, but should suffer from a slow rate of speed relative to other weapons. letting long range shots be evaded... unless taged or narced.
Things like this would turn the LRM into much more of a support weapon. One that damages the entire mech and not be so focused on the CT. placement of the mech and your target location become much more important for landing the long shot. with greater engagement ranges supported by units with longer range tag. scouting and skillful group maneuvering becomes much more important. along with the damage spread comes a reduced lethality letting players make positional mistakes that are not fatal within 5 seconds. lessen screen shake by 90%
Then after a while re-balance damage. i favor lowering it or leaving it the same and upping the rate of fire/range for AMS.