Figure an average of 25 games per account. Each game takes 2 minutes and 15 seconds menu-to-menu. That's an hour per account, meaning 7 hours for the trial accounts and another hour for your the intended gamertag. Add an hour for each additional gamertag getting to GOAT. Add some time to create and upgrade all the accounts. This is for the best case scenario, with zero games played on the intended gamertag and dual 360 setup. Add a couple hours coordination time if done with a buddy. This may sound like a lot but keep in mind it's guaranteed. There are a ton of people that will never get goat because trueskill is screwed up, even though they did pretty good back in the day when there were people still online playing this.
For the Madden 07 import draft thing, there is a slick way of doing that described in this thread(copy-paste and remove spaces)
achieve 360points .com/forums/showpost.php?p=581622&postcount=10