Is there some kind of local need for this? Most people with Teslas know they’re within range to charge at home, then make it to work and back. Does he really expect people to stop at his place for a while to recharge? Where is his expected customer base already getting their recharge from? Why would they switch to him?
Most recharge stations that are out there, are businesses with free chargers in the parking lot, or have the chargers as an auxiliary to their main business. Going all-in on this sounds like a pretty dumb idea.
This would be primarily for EV's other than Tesla. Tesla's would be able to use the station with a $450 CHAdeMO adapter. This would likely be a last resort for Tesla owners.
As you point out fast charging, is a last resort. Most people charge at work or home. It would seem to me generating foot traffic for the convenience store would be a problem.