i saw in the comments someone asking for a bank-like option for equips and i'm writing this as a bump. also bumping aronzei's comment for a buy-back feature. Both of these options would make both the loot interface cleaner and equipment management more acessible.
I think the chance of getting a pet from bosses is too low, besides, taking in account the chance of facing a boss and actually beating it, it's quite hard to get a pet, in my opinion. I believe the best way to get a pet would be having a chance of getting one from a normal or at least a special monster, about the same chance of getting one from a boss, maybe lower, and a boss would have a greater chance of providing a pet. The pet from the boss would in this case probably have better stats than one from a special monster.
 "Zombo Buster"){kind=icon}
 "Battle without End"){kind=icon}
 "Demons vs Fairyland"){kind=icon}