Hi - I don't have a cafe or restaurant but have worked in them in various capacities and managed a sandwich shop/catering facility/cafe for a couple of years and am just going to play devil's advocate.
Have you worked in cafes/ restaurants for a length of time? In a capacity more than weekend waitressing? If you have, great, you probably know just how much work is involved. If you haven't, do you really know how much work will be involved? Especially while you get established? I'm sorry if I sound like a patronising old cow (it's not my intention) but my brother has recently been for two interviews to manage cafe/ bistro type places where the people have either bought it as a retirement-type jolly or "to fit in with the family". Both of us thought they were going to be rather once they got up and running.
I do know of places that ran quite well without the owners present but a) they were established and b) they had staff that had been there a long time, gave a monkeys and were able to manage themselves and unexpected situations without too much input. It took a long time for the owners to reach that stage.