If the Rangers go back to a zone style defense the team will tighten up in it's own end---and yeah you do want D who can move the puck smartly and quickly up the ice and having a hard forecheck is a really good thing as well. The game is predicated these days not only on puck possession but when you don't have possession of taking time and space away from the other side. A passive defensive system even if it's a zone is not going to work well. The team still has to pressure the puck.
Keeping in mind as well---that with so many younger players it might take another year or so for the Rangers to get back to even contending for a playoff spot. In the meantime those younger players are going to need a coaching staff that can work with them to develop better and faster. This is part of what Mr. Quinn is going to be asked to do. It's not something that I think that Mr. Sutter or Mr. Hitchcock would have patience for and those guys need veterans and those guys were used to elite players like Seguin, Benn, Kopitar, Doughty. They're used to winning at the NHL level and any season their teams are not contenders is a lost season for them.
Is Quinn the absolutely best guy or even good enough? Well---time is going to tell but there would be these same questions about any other guy the Rangers might have chosen so there's no reason to sweat or fret too much about this. We're not going to find out how well it works until we see his team in action for an extended period of time.