As for crime more generally, I kind of doubt deBlasio will actually change that much in the police department (besides surface changes, like getting rid of Stop-and-Frisk), so I don't think it'll shift that much. Crime has a noted tendency to follow generational trends; ~20 years after heightened birth rates (like in the early 2000s), there's usually a rise in crime. So deBlasio might have some issues in his 2nd-3rd terms as mayor, but I doubt this coming term will be marked by some kind of rise in crime.
Maybe. Maybe not. I'm inclined to think stop and frisk had a significant effect on reducing crime. But it was unbelievably unconstitutional. I mean I heard about it at thought it was messed up but when I saw the actual statistics I was stunned such a practice could go on for YEARS in the nations largest city. It really makes me wonder about this whole Constitution thing. It's a bit of a joke.
http://www.nyclu.org/content/stop-and-frisk-dataThat has to be some of the most ineffective policing I've ever seen. That's just putting out a minority dragnet and seeing what turns up.