These are all fine:- "Pass the salt please" "Can you pass the salt please" "Can you please pass the salt" Do not use "over" in any of them.

At some deep structure level, they're different. If you really wanted to, you could analyse the first and conclude that you're asking to person to do something (pass over the salt) for your benefit. In the second, you're asking the person to pass over the salt in a particular direction (yours). But it's not really worth thinking about. In practical terms, they have exactly the same meaning. What's more, they both seem unnecessarily wordy : in the real world, most of us would just say "Pass me the salt".

I believe "pass over" is a separable phrasal verb. So we would say... Pass the salt over to me. Edit: that is not exactly correct. I meant to say "pass to" is separable. "pass over" is a different phrasal verb and has a couple of different meanings. It is also sometimes separable. I couldn't find "pass over to" in the dictionary, but we often use it to mean "pass to". Edit: also... "Pass the salt to me." you can use "over", but you don't need it. We wouldn't use "for" because, although you are passing it for my sake, the emphasis is usually on the action. "Throw the ball TO me"