Phrase 1
Are we good?/We're good?
I don't hear "We're good?" often, and admittedly, it sounds a little strange to me. But I believe that it can work or that it is understandable. Oddly enough, the slang/incorrect "We good?" sounds more natural/popular than "We're good?" (but that's my opinion). As for "Are we good?",
this can have a few different meanings.
Example 1.
A man and a woman have had a small disagreement. The man becomes nervous that their relationship might end and asks "Are we good?"
He could be asking "Is our relationship ok?", or it could mean "Are you still mad at me?"
Example 2.
Some friends are being chased by a monster through the woods. They finally escape the woods, and some asks "Are we good?" He is asking, "Is it safe?" or "Are we safe?"
Example 3.
A family has packed their stuff in the car and everyone is eager to leave and begin their trip. The dad, at the wheel, asks "Are we good?"
In other words, he is asking "Is everyone ready?", "Is everyone ready to go?".
Phrase 2
Are we good to go?
My impression is that this has the same meaning as example 3 above.
It could also mean "Are we ready to begin?", as in begin to watch a movie, a class, or other things that can start.
So Phrase 2 is usually used to ask if we can begin something, like trip or a movie. It can refer to physical movement, but it doesn't have to (like watching a movie). But it would not be used in the sense of examples 1 and 2.
Best Answer
for good means you are leaving for the last time. You will NEVER come back.
Check this definition: for good