Personally, the use of dimmable Fluorescent
lamps, is OK, but, it really depends on how long(over a 24/7 period), that they are going to be held at a dimmed level, as the
HF ballast is not meant to be run at a large level of dimming for long periods.
Also depends on what type of tubes you are dimming too.
Daylight dimming is a good way of reducing
the cost of running a large bank of Fluoro's,
during the day, as long as the equipment is allowed to run at full voltage for at least an hour each day, or the life of the tubes and ballasts, will be drastically shortened.
With respect to lighting a Restaurant, by F/lighting, it really depends on what sort of restaurant, it is, fluorescent light does not lend itself to being the most romantic of lighting forms.