Right. I can't get on to the other things I want to talk about until I finish this, 'cos that's how my brain works.
So: Mr. Finch....
Well, I actually have fewer problems with him than I do with the Ninjahobo. For one thing, he at least looks right. My concern is mostly about his motivation.
In the original show, Mr. Finch is a millionaire genius who built a computer supersurveillance system for the US government and left himself a backdoor into it for entirely altruistic reasons.
The bit I have a problem with here is the altruism. It's not that I object to altruistic characters, it's just that government supersurveillance =/= altruism to my mind. Moreover, what kind of altruistic and naive genius (he'd need to be very naive to build a system like that for altruistic reasons) would then hire a ninjahobo? Surely there are more competent and functional individuals he could employ to be Batman for him? Bear in mind that he's very very rich - now money may not buy everything, but it'll surely buy you a very competent and discreet mercenary who isn't drunk and homeless - and buy their continued silence, for that matter.
No. Mr. Finch is not entirely altruistic. I don't know that his precise motivations matter - he may be a well-intentioned extremist, have a vendetta against some particular criminal organisation, or have a sort of classist hatred of criminals as "scum" - but he's definitely got an agenda. That agenda is why he goes with Ninjahobo - he wants someone who won't ask too many questions about why he's doing what he's doing, someone he feels he can manipulate reasonably easily.
"Manipulate" is the key word here. We've set up the kind of character in the refigured Ninjahobo who isn't really going to want to be Batman. He wants to be left alone to drink himself to death, and he's not afraid to seriously hurt people for that to happen. Now the original Ninjahobo Refuses the Call, to be sure - but our Ninjahobo would probably refuse it utterly. So how would Finch go about getting him onside?
Well, I think he'd probably engineer all the situations that Ninjahobo gets into until he agrees to start being ?Batman-for-hire. That first fight on the train? Set up by Finch. The situation immediately after the first refusal where Ninjahobo is made to believe someone's being murdered next door? Our Finch would have him eavesdrop or walk in on a real murder (or attempted murder) and see how he reacts. After he's gauged Ninjahobo's skills, he'll offer him money to do what he's already been doing.
This isn't too much of a stretch for a guy who builds computer supersurveillance systems, after all.