Wisconsin has one inspector per locker room usually. More on larger events.
Inspectors check bags as they arrive in the locker rooms.
Nothing with caffeine allowed. That goes for drinks or caffeine/stimulants in powder or pill form.Electrolyte beverages like Gatorade are allowed. Only water in the corner during the fight.
Just the three you have listed.
No
Tape, gauze and finishing tape (If they use it) only unless administered by the ringside physician after the bout.