jrider, I would ditch those pallets so fast you'd wonder how they got away. You probably also know that I hate pallets for a couple reasons. 1. They look like h... 2. They can be dangerous when taking wood off because they many times have a tendency to break and that can wreck havoc with knees and ankles or even falling and breaking an arm or wrist. 3. They tend to teach you some bad words. 4. Unless they are plastic, they usually don't last long. 5. I can probably come up with more reasons but that is enough for me. I would not hesitate to use the pavers but not in the way you have them close together. I would make 2 runners and stack the wood on those which would mean they would go a lot further than if stacked close together. This is basically what we do; use runners. Only in our case I don't like spending dollars for the runners to just stack wood on. So I either cut saplings or use mostly straight limbs or lately when I cut some dead pine on our place I'll simply cut those into 10' lengths and lay down two of those to stack on. It is difficult to beat the price on these and they work great.
I'm still a big fan of pallets for firewood racks, but with the proper blocking and attachment Simple pallet firewood rack going onto year three for some of these racks, none have rotted out, though I have moved a few to give better access between them, and changed some of the roofing. My current favorite is old above ground pool steel walls, the perfect width and very durable. made of a thicker gage of steel than the roofing. I guess the big difference for me is that I don't walk on them, just stack wood on them