This is why I asked people to go into detail - it makes each suggestion much more useful.
For example - it isn't just reserving pool loungers - it is forgetting to pick up your used towel. As stated by jacdenv, i am sure half the time it was just someone leaving their wet towel behind.
The same with "slamming the door" (which can happen very easily when the balcony door is left open).
In the buffett - how about when there are no tables - Isn't it common courtesy to invite someone to sit down with you? especially if you are alone. Should a person really have to ask, "do you mind if i join you?"
The question is - is there a way to ask where they won't feel obligated if they don't feel like eating at your table (for whatever reason)?
What is the proper way to ask someone in the buffet if they would care to join you?
Like you could say, "you are welcome to sit here if you'd like." It kind of takes the obligatory edge off, better than, "would you like to sit with me?" if you get my drift.