Its a huge show. Here's the website
http://quilts.com/ It should answer a lot of your questions. There will also be a vendor list closer in to the show dates so you know who will be there. There is a list of teachers on the site now. But, yes, lots of big names come to Quilt Festival
Staying downtown is the way to go especially if you are taking classes. Houston traffic is not for the faint of heart. All the big hotels have shuttles. Some are close enough to walk. There are shuttles from the airport to the hotels so you don't need a rental car if you are staying downtown.