If I gain control of my opponent's equipped creature, does the equipment stay attached? If so, can I equip another one of my creatures? I doubt the latter since it would seem you'd need to control the equipment through some effect to do that.
Yes, it stays equipped.
No, you can not equip another one of your creatures since you do not control the equipment.
Your opponent can move the equipment to one of their creatures whenever they gain priority and mana (assuming they have a creature to move it to).
EDIT: Its also noteworthy that your opponent gains all triggers from things like Sword of Fire and Ice as well as they still control when the counters are removed from Umezawa's Jitte, ect..