+ As always, this AU has the DCAU as its base. I don't think it follows most of JL; it breaks off after Superman: the Animated Series. This is subject to change.
+ Bruce decided to follow his dad's footsteps and became a doctor instead. What this meant for Wayne Enterprises is that Bruce diminished his role in the company besides a major stockholder and a yes man for decision-making; instead, he spends most of his time in the office or in the hospital or at the Manor with his family.
+ He's a heck of a lot more nerdy than in canon, simply because he spent his life in med school + residency + fellowship and didn't finish his education until he was about 30-31. (I play Bruce as about 35, so... he's been a doctor for four years.)
+ He's adopted both Dick & Tim and taken major pains to make sure they both finish their education. Robin & Nightwing are more physical fighters than Batman - especially Nightwing - though Bruce can hold his own in battle too.
+ I keep imagining him as more of an Oracle than a brawler; he knows information on all of his foes and acts accordingly. Of course, since Batman's nerdier... I feel bad suggesting this, but the Riddler might be more of a foe than the Joker to this world's Batman.
+ He's always struggling between work, family, and crimefighting. IT IS A ETERNAL STRUGGLE that he doesn't have in canon because unlike business, he can't hold off his patients for another day. There have been millions of conversations where he's chilling in the Batmobile and patiently telling nurses and nurse practitioners how to deal with a patient while Robin and Nightwing are off fighting someone else.
+ In the end, Bruce wants to have his cake and eat it too, but as if that'll easily happen.