If you leave the neutraliser on to long it can damage the perm and it will fall out. You should always get a lotion that is suited to your hair type and only leave it on as long as the manufacturer's...
every month you get a perm. if you go to a salon they give you perms every two weeks. so you can get a perm every two weeks if you want . Even though you may relax your hair as you like it is not...
don't wash your hair (or go swimming) for 3 days after the perm is given other than that, you can do anything- get feathers, straighten it, curl it (though i don't know why you would..), dye it, etc