It's no myth. However, the development of players is a coaching skill and the problem is that many question the ability of certain coaches to develop talent.
Well we can't really be certain of anything but I know that reports had him practicing at Guard before the season. He's certainly big enough but I'm no expert on projecting OL.
I like Walker's potential at OT as well. I agree about the interior line and I think tbat Seymour and Rodriguez will end up giving us a significant boost there. Rivers can also play guard if we need him to so there that as well.