Word. I've been trying to do similar in my life and when I do make the effort to raise myself to the same level as those I am greeting the interaction is so much more fulfilling for us both.

No, it would not be good. There is a difference between brother, best friend, friend, buddy, etc. You can be friendly to people without diminishing what those words actually mean. Not everything has to be "awesome", some things are just great, good or even okay. And that is literally okay.

It's all fun and games until someone is incredibly offended because she actually identifies as a genderfluid demisexual wolf in a human body and you just referred to her as "sister"

I like using buddy or ma'am. Everyone can be my buddy until they do some action that proves otherwise.

Non native. Does ma'am have the same ring as "buddy"? It always sounded somehow deferential to me

No, ma’am is the female equivalent of sir. They’re formal terms, not familiar like “buddy”

This is my go to as well.