so I'm not sure how much of our experience is valid in your very competitive and finicky business. We just rejected a little Bistro we were thinking about buying because it was one of those once-in-a-decade opportunities that you just have to look at. It is almost perfect in every respect, but in the end it is still a restaurant and will still require lots of hard work, very long hours, and constant supervision.
Generally, I avoid employees like the plague as the number of problems in a business increases exponentially with employees. Once you hire one, you come under the authority of innumerable agencies, regulations, and laws that increase costs and hinder your actions. I've always built businesses on a partnership model (I call it the law firm model). Doing it this way, I've certainly made less money for myself but everybody has made far more overall, and that's one of the factors that has always attracted buyers when I'm ready to move on to the next thing.
Turnover can wipe out your bottom line and the only businesses that run with high turnover for long are those that exploit their workers. The more skill required, the worse it gets. OTOH, it usually takes more than money to keep good people in a dynamic employment environment like food & beverage. One thing I've found to help this is to make good employees out of average employees. It takes longer and costs more, but I think the returns are sufficient justification and when those inevitable and unforeseeable disasters strike, they are the people that will go above and beyond helping you get through it.