I didn't see a this particular game, but I've seen plenty of Rielly in general. Rielly playing poorly in one game isn't a big deal, he has good and bad nights like anyone else. Still, people should realize that he's a player with strengths and weaknesses. His strengths include elite skating, vision and puck handling. His weaknesses include a mediocre shot, lack of physicality, and below average defence. Don't expect him to be a dominant 2-way dman right now, because he clearly isn't. He's a phenomenal puck handler, skater, puck mover, etc. who has work to do on other areas of his game.
As for the Rielly/Hamilton pairing, you have to think that they have the potential to be great together, but time will tell if they can develop chemistry. If they can't pairing Rielly with a defensive dman like Harrington or Reinhart could be a good idea. One issue, though, is that other than Hamilton, the only right handed dman on the team is Murphy, and Rielly/Murphy would be a terrible pairing. So if he doesn't work with Hamilton, he'll have to play with another left shot.
Long term, I do sort of wonder how Rielly, Phaneuf, Gardiner and Liles will all play on the same team. It could easily be the case that non of those guys play particularly well together, they're all risk takers who love to handle the puck. We have a lot of talented dmen (in terms of current players and prospects combined), but I think some trades may be necessary over time to come up with a unit that works.