1) ~3-4 seconds (longer for higher capacity mags, eg. GBB uzi (~7-9 sec)).
2) Yes it "should" be able to. I believe with the TM Hi-Capas you can get 2 and a half mags out of one fill however my KSC G19 goes 1 mag usually, ~1 and a half mags at the max
3) I don't know if those exist and if you find one (for a KSC G19) please PM me. You might however be able to use those pistol mag speedloader things but that's probably a long shot.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE