"Excuse me" is the best option, maybe with a "please" on the end to be super-polite. Pro-tip: since you are going to the bathroom, if you're feeling confident, you could also try " 'scuse me mate, got to see a man about a horse" :^)

None of your suggestions are quite right: 'Hey' is a very informal way of attracting someone's attention. It's not appropriate for this situation, and if you said this to a fellow passenger it could be seen as rude. Conversations with strangers start with an 'Excuse me', not a 'Hey'. By contrast, 'sir' is over-formal. We don't normally use 'sir' unless we have to. The flight attendants would address the passengers as 'sir' or 'madam' because they're required to as part of their job, but passengers wouldn't address each other in this way. None of your expressions with 'pass' work either, unfortunately. You could say something like 'Excuse me, could I just get out/ get past you?', but in reality nobody ever gets as far as asking a complete question. To be honest, the only thing you need to say is a polite 'Excuse me' or 'Sorry', accompanied by the appropriate body language of preparing to stand up, and other passenger will always get the message. Or failing that, book an aisle seat?

Hi, none of them are used, or at least I don't recall hearing them. You could say "excuse me, could let me pass" or "let me by" but a better option would be "excuse me, can I get past" or "excuse me, can I get through"

I would normally just start attending up and say "Excuse me". There is no real need to turn it into a question.

You don't need to ask a question just saying "please excuse me " and make the body language of passing by will work. I don't agree with the poster who said that saying "sir" or "ma'am" is too formal. Those are manners that people don't use much anymore in certain places but where I come from more people say "sir" and "ma'am" than not so you would not be looked down upon for addressing someone like this.