@starcraftguy1 keegan has these two mods
https://www.gta5-mods.com/weapons/tx-15-dml-animated-replace
https://www.gta5-mods.com/weapons/tx-15-from-eft-animated-replace
these are the only two mk2 carbine replaces that i know of on the site, most other replaces are only available for money.
as for not being able to use sights i cant really help as i dont use first person so i havent tried to but you can change the values of scope offset to make the sights work you would have to look up a guide as i have no clue how to do it

@Forrest-Gimp idk if its what you are looking for but VEDGA is what i use, and since the latest update it even changes some gangs, i dont remember any other specific details about the mod but its the only dispatch mod that ive personally used and can recommend, Im sure theres more out there though
Heres the mod link so you can check it out for yourself
https://www.gta5-mods.com/misc/vanilla-expanded-dispatch-beta-1-0

@Losthegamer01 visualV and visual Vanilla are really the only free graphic mods as far as i know and they are both pretty good. They aren't as realistic as something like natural vision but they are good free options and at least in visual vanillas case dont hurt the fps too much. I'd try both and see what you like more.

@CaptainbryanYT this mod seems to be a patreon mod from julioNIB and it also seems to be incredibly outdated (last updated 2016 i think) so it most likely wont work with the latest game version

@B1ggs open iv is required in order to mod the game its what allows you to open rpf files and edit them the reason you didnt need it to install simple zombies is because its just a script

@LSPDhighway the closest thing ive found is in mpsmuggler_male_p.rpf but its only the goggle lens for some reason probably not helpful but thought id let you know

@SecretCookie if you have them try disabling your scripts and try, i know thats what fixed the issue when it happened to me i think it may have been enable interiors as that script breaks a bunch of things in story mode but it could be another script.

@Arkinator as curtis said above the cars dont have models so they arent able to be spawned you have to wait for them to actually release on pc whenever that actually happens

@madkirk74 there should be an option to disable despawn off dlc vehicles that might be whats happening

@Deadboy-l i use Hanako's npc cover animations https://www.gta5-mods.com/misc/ai-cover-animations-mod-hanako
i think its great, its meant for use with mp characters but from what ive seen it works just fine with the protags