The area sounds ok for mosses but the main considerations would be the substrate the moss would go on top of and the amount of moisture that would be supplied. The real limiting factor for temperate moss species is temperature not amount of sunlight. If you can maintain the colonies at a cool termperature they can handle direct sun exposure.

Thanks a lot for your help. The other day I filled in the areas around the pavers with MiracleGro to 1.5-2", to make the surface level for hauling the trashcan. Reading yesterday on Mossacres lead me to believe that this won't work for moss, although I'm not sure if I should remove it entirely or amend it substantially with other materials.

Wrt temperature, we are in northern VA and it is currently in the 90s. I have noticed moss growing around the bases of some potted Japanese maples I have, but that's of course in very small areas. I'm thinking I'd better wait until temps drop in the fall...If the moss is established by next summer, would it be able to handle 90 degree temps?

Remove the MiracleGro-mosses do well on poor soils. The nitrogen levels in most commercial mixes would burn the mosses. The best substrate for most mosses is either peat moss or coir that is applied at around 1/4 to 1/2 inch depth. Beneath this acidic cover can be a sand base or just the regular soil that was in place.
What is your water quality? If your water pH is neutral to slightly acidic and it is NOT SOFTENED WATER then I would go ahead and try some of the shadier spots for moss. But mist it daily especially when it is the hottest part of the day.
I have a moss species from Georgia that was getting 3-4 hours of direct sun and it would even get fairly dry on the surface of the colony but I would pour r/o water on it and let it drain off during midday when the sun was hottest. This colony was left exposed to some narly heat a month or so ago when temps were hitting close to 100 in our area. In your area it is the humidity that really helps the mosses deal with the high heat even though these same mosses must handle snow cover in winter. They are alot tougher than most people believe and as I have learned!

I visited one of the best local nurseries today and got a bag of spaghnum peat. They also sold "organic peat" (actually I think it was "organic peat hummus") but customer service said to go with the spaghnum as it would be a bit more acidic. We laid the pavers on 2-3 inches of stone dust, and below that is the natural clay soil (also acidic). I hope stone dust is close enough to sand. Humidity we have in abundance. According to the nursery guy, our water is neutral to slightly acidic but is softened by the county. The moss that grows at the base of my Japanese maples has survived being watered with the hose water...although I wouldn't say it has spread quickly or all over. Is it still worth it to try in the path area? I don't think I could collect enough rain water to keep things sufficiently moist for the entire path.

You're right about the toughness of moss! I was tending to the plants on our deck yesterday, which gets very hot and sunny, although is slightly shielded by a lattice. No one on the block has had any plants survive on their decks. The only thing doing well on our's is a mandevilla. At least that's what I thought until I noticed that the soil around the base of a miniature rose was covered in moss. It looks quite healthy to me and appears to be doing better than most of the roses. :-)