I know this is common sense, but everyone should be maxing out rapport for all their characters. You can get so many rubies. I've received hundreds of rubies so far. And it's so easy to max out rapport. It only takes 3 or so runs to max out a character.
I haven't done it for any of my Cs, but all my As have been getting max rapport at least. I should start working on Bs when I get them...
Also, I pulled Red Snow from the login ticket; I can see why the later versions of her are so good. Might keep her around anyway as an arena helper.