how long was it at 104F? It takes some time to bring the internal egg temperature as high as the incubator temperature.. so it could depend if it was a quick spike or an extended period of time (days?). I think your eggs are going to be okay

I have had a spike that high and had chicks hatch
make sure you take the temperature at the same level as the top of the egg, the bottom of the egg will be a few degrees lower.
when you add water, the temperature goes down. so if you remove water, you may see an overall spike and have to balance it out again - just keep it in mind.
I think 30% is about perfect humidity for my area.. I live in Oregon and my house humidity is about 50%, I also leave the 2 air vents open the whole time which helps the incubator regulate humidity from the room it is in.
if you run around 49% for a while, it's okay it won't harm anything. it is all about the average total humidity - the goal here is that the eggs evaporate and lose 13% of their water weight (I weigh the eggs to track weight). so, if it is too high for a time, you can lower it for the next X amount of days to make up for it and even it out overall