Just me babbling again----I generally use needles between 40-43 gauge. I have used crown needles and like them but find that they seem to wear out quickly. As for rooting----I started back in the years when rooting was from the middle. I have continued to it that way. It works for me. I have found the key is to have quality mohair. In my tutorial, you will see me rooting from the middle. You would root the way that works for you. The important part is following the direction that the needle is going.
If anyone is having trouble with rooting and would like help, just send a pm and I will be more than happy to guide you through.