Badkat - I think there is no need to worry about new leaks if you avoid creating new holes in your roof.
You can use very strong 3M industrial 2-sided bonding tape to attach mounts for traditional panels to your roof, or you can use flexible panels that bond directly to your roof - see below. You're looking at a 288 watt system on my 1999 Safari. Here is a link to learn more about the 3M tape - http://solutions.3m.com/wps/portal/3...apes/VHB-Tape/
You should be able to rout the cabling through your refrigerator vent - again see below.
So unless you have something unusual going on, there should be no need to penetrate your roof at all. I sure didn't.