You want to wax for the protection of the gelcoat/paint. You don't want the slipperiness that is normally assosciated with wax though. That's where a non-skid type wax comes in. I've only used the Woody Wax although there are others out there that have non-slip properties as well. The Woody Wax seems to be a favorite of many. I got mine here: MyBoatStore.com - Proven boat care, finishing, waxing, and maintenance products.
And I also buy my Poliglow from them which works well on an older boat but you really don't want to use on the deck.
It sounds like you need some further backing, probably with 1/4" plywood or better, in a wide pattern on the inside of the transom to distribute the load stresses of the O/b better. Depending upon access to the area, that might be as simple as rebedding the bolts for the O/b bracket with a sheet of plywood inside to distribute the load or it could be, as they say in the Navy, a full-fledged evolution.
If you've other priorities and plan on restoring the well at some point in the near future I'd motor minimally and gently.
If you don't have an absolute blast with this boat you'll likely be the first person who has not!
You might PM Jim when you get enough posts in to qualify for PM'ing. I think it's ten required with the Song Chain in Off Topic being a good way to get there. Jim is here infrequently but is a great and helpful member. Feel free to PM me as well if you think I may be of service to you.