Removing= the door panel is no big deal - the R&R of the seat control is a 30 minute or less job in your garage. My only advice is to get a handful of spare door clips - they tend to break. On the seat ventilation part, yeah, it's odd for that to break, but my guess is someone just kicked it getting in or out of the back seat. My kid's C240 has a broken cover on the back of the passenger seat - it won't stay screwed in place. Her friend kick it when they get in an out of the back seat.
Oh, and I really wish I had ventilated seats - black leather with a black soft top, and a dark blue body is not a good combination for our hot Southern summers! My wife had a Lexus with ventilated seats and it did help, though for some reason, it always made me feel like I had wet my pants...