I owned a quilt shop for 5 years and as others have said, its a 24/7/365 endeavor. Do your homework & research before jumping in. It's a HUGE investment. It's good that you have retail knowledge & experience.
IMHO, I would suggest starting out online and get yourself established because most of the competition really is online. That way, hopefully you can minimize your overhead expenses and it won't really matter if you have local support or not. From my experience, guild members and local quilters are very fickle; they want to have a quilt shop nearby but won't support it. Go figure. . . . .
Good luck -