The compost pile should be turned and kept moist regularly otherwise it takes a very long time for it to compost down. As for the rest I am no expert on Lasagna Gardening but I am sure where you are located would help any of the experts that are here answer your questions.

I don't think your compost being on a rock ledge is what would keep it from finishing. There are three elements to it: brown/green mix (carbon-nitrogen ratio), moisture, and air. If all those are in balance you should get compost in well under a year. What does the pile look like? Can you identify what you originally put in? What's not decomposing? Is it dry, wet, how does it smell? How big is it?

I'm going to guess it needs more greens (fresh vegetation, kitchen scraps etc.) and maybe some moisture. That's usually what happens.

You could do lasagna now to plant in using this half composted stuff as a layer, but it's getting late to plant unless you are way north, so it may be best to just plant in the ground.

The compost pile being on ledge is not a problem, people have built compost pile4s on concrete slabs with no problems.

Pat Lanza built her Lasagna beds and planted in them right away. Were I to build a Lasagna bed I would go to9 the original source to learn how to do that, if possible.

This link will take you to Pat Lanza's article on Lasagna Gardening.

http://ourgardengang.tripod.com/lasagna_gardening.htm

kimmq is kimmsr