Sqe33k!! = Squeek
Sw33tness!! = Sweetness!!
heavi3z = heavies
bad455 mecha troopz = badass mecha troops
Wo4h = Woah
Largo is more than chivalrous enough that he's not going to let a little girl unload, open and dump out all those pork rinds on her own. I think it'd be spurious to imply that largo's prints were NOT on the bags.
As for Yuki, if your magical gift is stealing, i don't think it's unreasonable that she is able to not leave traces of fingerprints without even thinking about it. As for largo... you scoop and dump out hundreds of pounds of pork rinds and see if YOU don't leave dirty greasy fingerprints everywhere :P