[Clipper]

It's been ruled that you can switch position of Items at any time you are not in combat, so others' turns are fine. You can use class abilities, such as Theft, at any time as well, unless the ability says otherwise. The only rule on timing of Theft is that neither the target nor the Thief may be in combat.

Other things you can do on others' turns include cursing people, playing GUALs on people and discarding your current Race or Class (but not playing a new one).

In a table in my flowcharts (see my signature), I have tried to categorise all the common actions into those that require it to be your turn or not. It's not officially reviewed, but everything I've put into that table is based on official rulings, so I'm fairly certain it's accurate.