[Arran]

I have heard that you can soak rags in evaporust or metal rescue, and apply those to the rust spots only, I don't think it will harm the paint but is definitely less risky then submerging the cabinet in one of those rust removers. Apparently molasses and water will remove rust without harming paint, but is the paint is already sort of compromised it may cause it to lift as you have to submerge the object. Clear coating over untreated rust is an exercise in futility, it just won't stick, and the rust will continue under the clear coat, it's best to remove and treat it if possible.
Regards
Arran