Re: Tires, Inventors have designed a wonder tool for RVers, it has dozens of uses, but is marketed for only one of them (Major failing on the marketing department) it's called an AWNING HOOK, a long metal rod with a bend at the end.. Use it to reach around behind the tire and "Snag" the cord. (or between duals).
Re: The outlet: I can think of 3 things...
Accessory (Tool) power for an air compressor or other tool you may need.
Inverter outlet (Used to power the rig off batteries, Several issues with this, like do not forget to disable converter, water, heater, 120 volt side of fridge and air conditioner if running on battery power,
Generator outlet for a poor man's transfer switch,,, (Where you switch by physically transferring the plug from the park pedestal to the outlet in teh power bay).
By the way.. I only use wheel covers if parked for extended (Month or more) time or if holiday parking (IE: I'll use them come July,, For one thing that will be a month's parking and the other is I'll project a patroitic slide on to them with my Mr. Christmas projectors for Independence day).