Yes, that piece about him voting no on Manchin-Toomey for procedural reasons is in my piece, but I’d argue that Reid should not have accepted funds from the NRA if he was truly in support of gun control measures like universal background checks. The NRA opposes universal background checks. From 50,000 feet, it looks bad.
As for your assessment of the legislation as “to gain Republicans favor,” I respectfully disagree. The parents of the kids who were murdered at Sandy Hook were very much in favor of Manchin-Toomey and were physically present in Washington D.C. to support it at the time. They were devastated when it failed to pass. http://ctmirror.org/2013/04/18/sandy-hook-parents-watch-gun-bill-dies-congress/
Gun control groups supported the legislation as well and still do, as there is talk of reviving it. The fact that it was bi-partisan was an intensely positive thing. Bi-partisan or executive order is the only way we will have movement on this issue unless the 2016 election really shakes things up in Congress. You’re correct about the filibuster being what defeated Manchin-Toomey.