Most pros update their bag every 1-2 years but when they do it under the same sponsor it goes mostly unnoticed. Unless the player wins and says how great his new putter, driver is. Obviously Rory going from Titleist to Nike is going to create some attention. But it's not like he's going from muscle backs to game improvement irons or something. Like I've said before, the biggest change might be the ball.
I think so too, but I don't think that is affecting his play. He just needs to get his head together. But as far as equipement impact I would think the ball would be the only thing to really force him to make adjustments. A high-end MB is a high-end MB and I'm sure Nike crafted his new irons to be indistinguishable from his old ones.