put the snake on papertowels or plain newsprint in a quarantine type setup until you find out what the blisters are and get them healed. do not apply neosporin the entire body--that is what is causing the scales to flake off individually--because of that this will be a messy and probably troublesome shed. do not squeeze or mess with the blistered areas.

shedding usually take about a week, from the time the belly goes pink to the time they actually shed the skin off but this shed may vary because of the flaking caused by the neosporin.

time between defecations will vary, depending on what and how much the snake is eating, how old it is and in what kind of physical condition and also whether the snake has internal parasites.

do make an appointment to see a herp vet asap. as noted you need to have him tested for internal parasites. the vet will also be able to diagnose and recommend treatment for the blisters.