Sharing a kids meal between two adults is still not unethical as long as the restaurant allows an adult to purchase a kids meal. I often get kids meals. Stealing napkins/condiments is stealing. Stealing is always stealing. I take enough for my family's use plus one or two more in case there is a spill.
And what is so wrong with tap water? It is clean. I mean, it's gross to get it from a public bathroom but not unethical. I don't drink tap water personally unless it has gone through my filter but that's because our water is gross here. There's nothing unethical with drinking tap water.
As long as the store has not put a disclaimer that only a certain amount may be bought by each person, no it isn't unethical. If I have an unlimited amount I can purchase and I have coupons that make my deodorant 50 cents each, I'm going to buy as many as I have coupons for. That's just being smart with your own money. Whether or not there is more for other people to purchase is the store's responsibility and not mine. Though I rarely remember to use a coupon so I'd never do it. I just don't find following the stores rules unethical if it means they run out. What if it is only 2 items but there aren't any more? Should they only buy 1 or leave them for someone else?
Lotions and soaps are meant to be used by the person staying in the room. Stealing towels and robes is stealing. Stealing is always unethical.