QBB is fine. The higher ROF makes it a good LMG for more aggressive LMG play
PDW is fine. Maybe try using it in its optimal range and you won't have a problem with recoil
Maybe the Vector could use some love. The MP7 has a faster reload, better range, better iron sights and the recoil doesn't seem that much worse then the Vector's. Just my opinion but I don't see any reason to use the Vector over the MP7.
Can't really comment on the S12 (although I barely ever see it online)
The Executioner is usable now but it is probably still the worst gun in the game although tbh I don't mind it that way. Anway I think that it's better to have it be a bit weaker rather then having a pocket sized one hit kill machine.
The Remi is annoying but there is no need to nerf it any more.
I don't really care what they do with the pistols anymore.