Maybe cleaned and inspected once or twice a year, you don't recoat anything. If you see cracks in the caulking or holes in the EPDM, have it fixed right away at the dealer. As you are The Most Unhandy Man in the World, kick back with a Dos Equis while they do the work. A coworker brings his 5th into the dealer before the 1st use of the year, they do all his maintenance, all he does is drop it off and pay the bill.
Like most things, if you keep up the maint on the roof, it's not a lot of work. All you have to do is inspect it and touch-up the caulk now and then. Clean it if you wish but it's not imperative.
Happy Motoring
Bob & Deb
W Ma.
12 F150 HD SCAB EcoBoost LB 4x4
14 Escape 5.0 TA