Re: repair shop for tohatsu
Can they? Yes. Will they? Up to the dealer. Since they're basically the same motor, I don't see why they would turn away the work.
I think the only difference between the Merc and Toh is that the Merc uses a "shift in tiller handle" gearshift whereas the Toh has the shift on the front of the motor (or side). But internally, all the parts are the same.
But if it's a warranty job, then no, they wouldn't be able to do warranty work on a non-Merc product (they'd have no way of filing a claim with Tohatsu if they aren't a Tohatsu dealer)