I think maintenance after 4 treatments is unrealistic. It usually takes 6 - 8 treatments spaced 8 weeks apart to clear all the hair on your face. You might want to look at the FAQ sticky at
http://cosmeticenhancementsforum.com...wforum.php?f=3.
As to your skin reacting differently this time, had you been exposed to the sun or changed medicines? They usually raise the intensity each time you have a treatment, so maybe you the intensity this last time was more than your skin can tolerate.
There is some belief that laser hair removal may stimulate hair growth, especially on the face. There are discussions about it on the forum I mentioned above. There are a couple of laser hair removal technicians on the forum, and if you post over there, they will give you some good information.