Well, congratulations on getting at least SOME chicks to hatch on your first attempt.
That's better than a lot of people manage btw, so don't feel too bad about it.
A couple of things that should improve your next hatch:
1. Your temps were definitely too low. 99.5 is for a fan assisted bator, but in a still air bator you should be aiming for 101.5 at the level of the tops of the eggs. With a still air bator, the air doesn't get whooshed about and sits still instead, with there being a big variance in temps from the top of the bator to the bottom. This is called thermal layering, cause hot air rises and cool air sinks to the bottom. The overall idea is still the same, to have the middle of your eggs sitting at a fairly steady 99.5, but you check this by measuring at the tops of the eggs, where it should be 101.5. So raise your temps a bit for the next hatch!
2. Your humidity was almost definitely too high. Some people will tell you they have good results incubating for the first 18 days at 60% humidity, just as some people will tell you they get good results at 20% humidity, but both groups are in the extreme minority. Most people get the best results by keeping their humidity somewhere between 30% and 45% for the first 18 days. I've always used fan assisted bators and my ideal humidity is 45%, but from what I've read here on BYC, still air styrofoam bators seem to do better at the lower end of the 30-45% recommendation. If I were you I think I'd aim for 35% humidity with my next incubation.
The rotten eggs most likely didn't affect the developing chicks. But next time you'll know to give each egg a good sniff every few days when you're either turning them or candling them. If a rotten egg bursts, all your good eggs will be coated in stinky bacteria laden goo and it'll take ages to clean them off and scrub your bator out and there'll still be a faint stink hanging around for ages. You really don't want that happening, so remember to do the sniff test. The sulphur smell given off by a bad egg is pretty much impossible to miss!
Oh, and of course, a warm welcome to BYC!
