So I have two Scum builds here, one that I've begun to have some success with, and the other is just me playing around with Fangs.
BB-Scum
http://xwing-builder.co.uk/view/566671/bb-scum
Triple Fang
BB-Scum and Triple Fang
K4 Security Droid should be Dengar crew. Zuckuss will be piling on the stress, so you might as well forget about trying to do greens to clear stress and trigger K4 and instead get re-rolls even on your valuable hard-3's.
Boba really wants Engine Upgrade and Advanced Proton Torpedoes are somewhat redundant with Autoblaster. Give him some bombs, Seismics or Ions, instead to help deal with swarms (and Extra Munitions if you don't mind giving up the initiative bid).
I like the idea of APT's on Kad, though I'm not sure how well it works in practice. I think I'd probably rather have Autothrusters on all of them than Stealth, though, to shore up defenses when you're not getting benefit from the Titles. The 3 points saved also gives Fenn an initiative bid.
I don't have the JM5000, so no Dengar, but I like the Boba advice. Also, with the Triple Fang, I was sort of building the list based somewhat on what I have, but good idea.