Hello Felicity, thanks for your email. I'm delighted to see you're an Aussie, as I am! I'm here in drenched Brissy! I don't really know anything about the business side of running a quilting business, but I can give you some food for thought from my experiences. I've worked in several patchwork businesses, throughout Australia, both as a staff member and tutor.
My first comment to make would be in all the time I've been associated with quilt shops, I've never met a quilt shop owner who gets any sewing or quilting done, once they've purchased the business. They never get the time to indulge in sewing for themselves. Most of the quilt shop owners I know (and I do know about a dozen) are often stressed to the ears, having to work long hours as it's cheaper for them to work behind the counter than to pay staff.
The second comment I'd make is that the coffee shop attached to the quilt shop is a super idea. One of the most successful quilt shops in Australia has a cafe/tea room under the same roof and it does very very well. That particular shop also has a lovely range of gifts for sale, so the three genres of quilting, light meals and gifts bring the customers in droves. They have about 12 staff working for them in any given week.
I would recommend that you get a business adviser to look over the business.
I wish you every success Felicity. Stay in touch and keep me posted. If you do go ahead, I'd love to come and visit your patchwork shop.
Cheerio for now