Use the Opera's online character planner (idk if version for FO:R is up yet, but the 2238 version will do as well), there you can see calculations for hit chance... What you wanna do is have max hit chance on max range with desired weapon. Personally, I use ST 6 char for BG burster and my weapons skill is 200% and its working perfectly fine (yes, undrugged), so I guess if you match the weapons ST requirement you should be OK with skill 180%, at least for TB, same for fast shot spammers.
Crit miss is affected by (low) LK, weapon deterioration and weapons skill (combined with ST requirement deficit ofc, if any). I don't think the skill affects weapon deterioration, tho I may be wrong about that.