US is not like other countries. Law allows servers to be paid very very low, like $2.13 an hour in some states. They depend on tips to live.
Florida Law does have a minimum wage including tip though doesn't it? So a server will never get less than$7.93 even if they get no tips as the employer has to make it up. In that case a server is no worse off than a CM working at the turnstyles. I know US wages are weird but I also don't think there should be an expectation that you need to tip hugely because you are ordering a small amount of food.
I do think the OP should order a dish each, so if they are only going to try Poutine or soup, at least get one each. Sharing an appetiser between four people does look a little cheap, but ordering an app each and no mains would be OK. Then maybe tip a little higher than normal but don't go crazy.
