If the average incubation temperature is a little high they can hatch early. If it is a little low, they can hatch late. I've had an egg pipping when I went into lockdown after 18 days. That egg hatched OK and the chick did well.
Different humidities work for different people. Mine usually jumps from 65% to 85% when mine start hatching. I don't remember what type of incubator you have, but make sure the top is on straight. I once got the top back on a bit wonky and my humidity dropped. Temperature was fine but not the humidity. That's how I knew something was wrong.
Humidity is controlled by surface area of the water. The more surface area, the higher the humidity should be. Setting up additional surface area should have helped. I'd need pitures or more information to even try to understand what happened.
Don't panic about them looking pitiful after hatch. Be patient an give them time to sort it out. You'd probably be a bit misshapen at hatch it you had been squeezed int hat tiny egg shell. I'm not saying there is not something wrong with that chick, but suggest giving it time. You may be pleasantly surprised.
Good luck with the rest of the hatch! It is extremely exciting and nerve-wracking, especially the first time.