Old Time Church and Restrictions

why is it that the people who go to older time church, they cant cut there hair, were pants or do all these things like not to wear makeup,my autistic daughter would never fit in here, i looked up on a few bible websites, 7 to be exact it said that you must not round your hair or shave a beard, which they all said applies to guys, they said the not wearing pants thing for women was said in the old testament, but most pentecostal church s sayas mine that the pants thing is a personal conviction. they say you will not be damned, also the hair thing is untrue because as long as you keep it long and healthy its okay, you may cut off the dead ends. so why all the restrictions, because they believe they have to follow Gods word exactly to live a holy life, not true, you can still be holy and not wear a skirt, cut your hair and wear makeup. how will this work for an autistic child. that's severe , these are all told to be personal convictions not godly ones