IMO, I've viewed Hal and Bruce as having an arm's length relationship, not fully friends, but not full blown rivals or even enemies either, perhaps frenemies instead. Bruce gets his rocks off on making everyone fear him, something that doesn't work on Hal who tends to find Bruce something of an asshole with that aforementioned scthick. As for Hal and Diana, I've never seen anything there, I've viewed them as comrades, teammates, nothing more, oh, I'm sure Hal could charm the tiara off Diana, but only if she allowed him to. However, seeing the two of them out of uniform and on a date would make for a cool story I think.