Your temperature range really depends on the species you are keeping. Same goes for your feeding schedule. Care should be taken when waking up a snake as to not startle the animal or instigate an instant feeding response. All of your questions really depend on the type of snake though. Generally a safe night time drop is anywhere from 10-15 degrees. Neonate snakes eat more often than adults. Adjusted according to metabolism and breeding season, etc.
Most snakes will eat every 7-10 days with the prey item depending on the size of the animal. Good luck when trying to decide if a snake is sleeping of just watching you- they don't have eyelids. As long as you are gentle with the snake and the individual is tame, you should be fine. There are some species and individuals that rarely ever tame and it will not matter if you startle it or are gentle with it because it will bite you no matter what.
Be more specific with your questions and we can help you more.
If you are looking into starting out, most snakes a person would start out with would not require a night drop, nor would the gecko. Adult snake feeding was already answered ....
And as for "waking up" .. If you are opening the tub or enclosure I'm sure they will wake up then, just move slowly.