I think that's right. I candled maybe five last night. I don't think any of the store bought ones are going to do anything, but the barnyard mix ones looked great! I could actually see the tiny start of the chick in one of them!! Just veins in the others. I also got rid of one of my eggs, it had little sappy places seeping out all over. That's great that so many of yours are developing!
I'm sorry about your RIR egg

That would be sad. I'm trying to prepare myself for the fact that hatching eggs is going to be a sad endeavor, probably, even if it mostly goes well. I'm most afraid of ones that make it to hatch and then don't pip. Having an egg break or leak in the incubator could put all your other eggs at risk, so I think you did the right thing. I have heard of people sealing cracks with wax, I think, but I don't know anything about it.