For your first question, don't think about it in the comic world. Yes, they gave us the reason that only Bruce trusts him to get it done or whatever and he's taking advantage of the world thinking he's dead. But real world reasoning is it wouldn't make sense to have him stop being a vigilante with a name people know him as and become one with a new name. They wanted to branch out and try other things and Dick simply changing his costume and name while doing literally the same thing doesn't help. Him becoming a spy and trying out this genre is branching out. I know people have been saying (me included lol) that him being a spy was a last minute decision, but apparently it wasn't because Seeley was contacted months before (I think around Forever Evil started maybe?). So they've apparently had this on their mind for a while.