So I added more hydraulic cement to the roof, so fix some of the cracking, and it seems good now. I still have rust on the end of the angle irons, but I'll have to figure out how t sand that off without harming the mortar. Made 3 pizzas yesterday, and they came out really good. I dried out the oven with smaller fires and then gradually brought the heat up. I did cover the oven with a tarp the other day, just incase any water wanted to get it.
So far the inside seems to be fine, but I worry a bit about the joints of the ledges hairline cracking a bit from the heat. There are hairline cracks throughout one course of bricks on the outer brick wall encasement (from the heat). I worry most about the ledges and ledge supports, because that is what is holding up the brick wall encasement. I'm sure it will hold though, but it's just the worry of having to do 4 pillars at the corners, instead of just making the base of the oven larger, along with a larger support slab.