Humidity does not need to stay at 75. 40-50 is good with a boost for sheds.
I thaw in hot water. Once thawed I drain the water and get fresh hot water (as hot as I can get out of the tap). I let them get as warm as possible then I feed trouble feeders first. That way the see the prey with the warmest heat signature as possible.
I dangle from the tail. The tail being held by the tongs adds distance and the snake will zero in on the prey. I have the best luck doing it that way.