1. i did not made quick reloads with magtoss but no bolt pull for open bolts because this detail is so small 99% people would not notice it

2. its correct, mosins have chamber so +1 is possible. in tarkov you can do reload it that way only through hideout (charging round into barrel and attaching full mag after), here it just spawns guns full always so it is what it is. you can't reload it to +1 again

3. gmod/arc9 issue, model/swep needs some time to initialize and load from hard drive properly. you can try enable asset precaching on startup in arc9 settings, but it leads to longer load times and potentionally crashes

4. idc about peeking, disable it in settings

5. everyone have different opinions on what ammo types should be, i follow arccw and arc9 standards. i guess it meant to be played in hl2 campgain without spawning ammo (so crossbow bolts and 357 ammo). 7.62x51 is used on lots of automatic guns yet also on some bolties so it should use same ammo type
i really don't know where "sniperpenetratedammo" type comes from, i don't like it since there's no legit ways to get it in game so i don't want to use it either
honestly, just enable infinite ammo in settings, this ♥♥♥♥ not worth time

1/2/3/4 - Ah, i see/Alright i can get around that
5)
-It weirdly displays as "sniperpenetratedammo" since its unobtainable for the player and only be used by combine sniper. Once you subscribe to one of the aforementioned weapon bases, it will simply display as "sniper ammo"
-Mainly for the HL2 campaign? That is what i'm thinking too! However, I was more into pushing ammo variety at it's full potential with the help of mods that speak "assignable npc custom ammo drop". But fine, for the sake of consistency, I will get along with this too

I also wanna say that despite ARC9 MW2019 fulfills most of my desires but one simply cannot outrival a crucial fact that this is the only weapon pack with shotguns that actually HIT target for once as far as i'm aware. So, just saying, you might wanna reconsider some of my suggestions...