Going down the list;
Dengar; doesn't really need a buff, he needs a better faction to make him a proper jack of all trades
Greedo; drop the thermal detonator part of Boba's leader and give it to Greedo, furthermore I think an easy fix for detonators is have them activate when the target takes their turn (similar to a DoT), or perhaps for uniqueness when the appliacant's turn starts (ex. Greedo applies 4 detonators on his AoE, then on Greedo's next turn all detonators he placed explodes), having all detonators go at once no matter how long they take to blow, or the simple thing of either make them irresistible or uncleanseable. Back on topic, Greedo doesn't need a guarantee double tap as his damage is actually not that bad, and the unique you suggested would be pointless, perhaps adding that if he gets a debuff resisted he gets potency up and turn meter (per debuff)
88- doesn't really need that much of a buff either as if the whole team is debuffed he's a beast, maybe his leader if anything
Bossk- poison gas is just Burning. Since the gas poisons more the longer exposed the target is, perhaps it could work like,"Target takes 5% max health (stacking) damage until the debuff expires" and making it around 3-4 turn long debuff. Also his kit should include something related to his Trandoshian biology, either something involving his claws and massive strength (Trandoshians are second in strength to Wookiees) or the fact that they can heal themselves (sometimes even regenerating limbs) by healing at the start of his turns, or something similar to Ima-Gun Di where he gets heals when he's crit
Lastley, Jango> Bossk