I just realized your email is not available...Oh well...
Yes, Cabarete would be much better - I think the type of tourists there are more inclined to actually leave a tip! But even there, I wouldn't count on making the same kind of money you would make in Toronto. But definitely enough to survive, especially if you don't have to pay rent. The minimum base salary for waiters is incredibly low, but in addition to the tips, you're meant to get a percentage of your sales (10% or 20% - I can't remember...)
In the various restaurants I worked at in Sosua, I was always the only female waiter, and always the only non-Dominican. You may think they only hire local males, but you could be wrong, as many tourists are intrigued to see non-locals working there and relieved to find someone who speaks English, French, German, etc. Getting the other staff to accept me was a battle in itself, but eventually most of them came around.
I worked at Juan Miranda's Caribbean Restaurant (now defunct), Guajiro's (which is now an Italian restaurant - the big one on the corner of Pedro Clisante opposite what used to be PJ's) and La Roca. Oh, and that yucky bar/restaurant in the lobby of Hotel Central, from where I was fired for not wanting to stand in the street and forcibly drag passers-by into the restaurant. That was my last waitressing job in Sosua, when, at my husband's request / demand, I began looking for more *serious* types of work...
In any case, I agree that Cabarete makes better sense - and would be more fun, too. You won't be able to really decide though until you're actually there and talking to people. You'll see once you start making friends and connections. You may even find something better not related to bar or restaurants.
When are you going back?