NFA Questions.

I'm looking to get an SBR, but I'm still a bit unsure about the legal stuff. <br><br>1. Do I need to be present for the transfer at the FFL? I'm in WV and I'm looking to buy from a place in MD, a bit of a drive.<br><br>2. Do I need to have my tax stamps if I move? I'll be moving to TX in about 8-10 months.<br><br>3. I already have a trust, but I'm the only person on it. What are the benefits of adding my wife? She doesn't really like guns, but I will be teaching my kids about firearms when they're older. <br><br>4. Is it true that if I buy a pistol and somehow am able to add a 16" barrel to it or something, it will be illegal? That doesn't really make sense to me. <br><br>Thanks!