you have an outdoor unaltered male cat????? That is really really irresponsible. You need to catch your cat, and get him neutered. Then, while he is recovering, he can get used to being in the house. Then, keep him indoors!!! If you are so scared he will run away or get hit, don't give him the opportunity. Yes, he will complain but he will get over it. We have successfully made several outdoor cats indoor only and as long as there is adequate stimulation (ie window perches, cat trees, toys) can't don't need to be outside. Also, if he wants to be outside leash train him, and then you can be outside with him.

But above all.. get him fixed!! I don't even want to think about all the kitten's he's probably already fathered this season

EDIT: I didn't see the part about your parents being allergic; truth be told, maybe you shouldn't have a cat if you can't keep him indoors with the family. If you parents are allergic, it's not anyone's fault, it's just the way it is. But if you do decide to keep him, he will have to be kept indoors for at LEAST two weeks to learn that your new home is where you are staying. I would even recommend a month.