We run into the same problems with our used brick steps and patio. It's hard to remove snow from the brick steps. The brick patio was set the correct way with the soil dug out (don't remember the depth but it was deep) and drainage stones put in then smaller stones on top of that followed by sand and brick on top. It was all machine compacted. It was beautiful for the first couple of years but the Winters have heaved the brick and some of the brick settled lower. Starting every Spring and continueing through till Winter we have to spray the patio with a weed killer due to weeds and grass growing up between the bricks. I have a small stone apron in front of one shed that heaves every Winter.

Although we don't have as much of an issue with winter heaving here in the south, we still have some. Before you remove that concrete, you might look into the stamped concrete that can basically "refinish" the existing walkway, making it look like stone, large tiles, brick, etc. We recently had our patio enlarged (it was formerly stamped concrete and we liked it), but decided to go with mortared fieldstone. They laid the stones right on top of the existing concrete. This might not work for everyone as it adds about 1.5-2 inches to the existing base. I can understand why you might also be concerned with being able to shovel the snow from a less smooth surface, which is why I recommend looking into the stamped concrete. Best of luck with the project.

At least with dry laid pavers you can reset them and level it back out. If the concrete cracks, it will always look patched.

A dark mortar struck about 3/4" deep looks very nice with stone. Would the grade allow for setting your stone on top of the existing concrete?

I'm back near square one since the contractor never provided an estimate and hasn't taken my calls, so now I have to find someone new, which will be difficult this time of year. I've also decided I'd like to change the location of the walkway from parallel to the house to more of a loop out into the front yard before connecting with the driveway. However, my desires raise another issue: the existing walk is mostly under an overhang and is level. If I loop it out into the yard, which slopes very slightly towards the house, any rain will follow the path to my front door. I know there are solutions (drains, regrading, etc.) but that also equates to more money. I appreciate your comments and will keep you posted on developments.