Yes. I may not be the best sailor, but I am a confident sailor.
Of course, I would need to do a little customization for extended travel and livability. The Mariner is MORC certified. I just have to be careful not to defeat her self-righting rating.
-Will (Dragonfly)
I think the Mariner is a fine little boat, but don't put too much credence in the MORC certification. It hard to image an under-30 footer with a reasonable interior and normal safety gear that would not qualify. In sub-20 footers, the trick is getting the full (galley head sleeping) kit-out to pass.
Safety-wise, a boat that length will be limited by its low freeboard, its short LOA which limits max speed and makes it more susceptible to capsize, and its transom mounted outboard being able to save it in a nasty confused seaway.
Personally I'd think that any trip that was going to rely on a lot of engine work would be nasty. So low-wind lake, canals, and rivers I'd pass on. Choose trips with lots of opportunities to gunk-hole, with just enough excitement to make it worthwhile, while still providing a bail-out.
Me, I think lapping the Apostle Islands would be a good one, if also a common choice. More off the beaten path, go around the Keweenaw Peninsula, just 100 miles east. A great combo of open water, great things to see, and some great places to spend the night. And Houghton is a great town.