Okay, chalk those up to "didn't see as useful" then. Though I really can't think of why someone would want a skinlink, and 'reduced weight' really has no benefit for a melee weapon. As for underbarrel weapons, yeah, I caught that -- just decided that it needed its own name, what with most melee weapons lacking a barrel and all.
One issue with Easy Breakdown, though: most melee weapons are designed to be a single piece of metal/wood/whatever, possibly with some attachments. If something is meant to be banged against something unyielding, involving multiple parts gives it weak points, risking it coming apart in use. (It would be like swinging a stack of Lego blocks against a table; it's bound to break up.) The rules don't actually address that, though, so it's one of those 'up to the GM' things I guess.
Still, thanks for spotting those. Carry on.