Re: Player speed and kill times.
They should increase base player speed and/or include sprint, but they need to resist the urge to decrease kill times.
We can argue that it took too long to kill people in Reach. Bungie went into the game saying they were looking for 'messier' fire-fights, that would see players use the environment and their AAs to battle back and forth for the kill. Personally, I was fine with it, it gave Reach a distinct flavor, but I can see how it turned off other players.
But part of what separates Halo from other shooters and makes it more skill-full is the increased time it takes to cut through somebody's shields for the killing shot(s). In a COD game (and to a point, in Halo 4... at least up to the time I stopped playing), if you get the drop on somebody, you win. If somebody scores that first shot, just put down the controller and speed up the time till respawn.
In Halo:CE through to Halo 3, if a player got the drop on you and you were better than them, you could turn the tide of battle in your favor and come out on top. There were no lucky kills, no 'happened to be in the right place' moments, there were just players who knew how to make the best use out of their environment, their weapons, and how to lead the battle in such a way that they could flip the advantage.
Re: 1-50 ranking system
We do need a ranking system of some kind back in Halo, as it places what separates Halo from the rest of the pack front and center - skill.
That said, people are kind of white-washing the issues that the 1-50 system had. Many players - including competitive players - were none too thrilled by the fact that you could go +15 in a match and derank, simply because of the performance of your team. People didn't like having their rank based on wins/losses (ESPECIALLY in Slayer... I think people in the Objective game types were ok with it, from my experience) because they felt it relied too much on factors outside their control. They wanted a ranking that rewarded individual performance.
Secondly, the point of the ranking system - based on the interviews with Bungie in the press and vidocs - was never to become a dick-measuring contest a la COD prestiges. You weren't supposed to be ashamed of being in the 20s or 30s, it was just to let you know where you stood relative to the people you were matched up with (if you're a 35, you know that they guys at 37 are probably a little better, the guys at 31 are moderately worse). But people made such a big fuckin deal out of them, I can understand why Bungie gradually, over the course of updates to Halo 3 and then ultimately the system in Reach said 'fuck this, feeding the egos of the hyper-competitive players isn't worth the stress to the rest of the audience', let alone all the account selling, deranking trolling bullshit that it lead to.
Do I want to see a 1-50 ranking system back in some form? Yes. But it needs to take into account a lot more stats (ie, if you go -4 but you have 20 goddamn assists, or 3 flag captures, or hell, DROVE the guy who had three flag captures, give the man a boost, not a derank) than wins/losses and/or K/D.
Honestly, I'd like to see a system where the rank beside your gamertag is locked at whatever the highest rank you've achieved in that playlist is, while the behind the scenes rank took both rank ups and rank downs into account. That could basically clue in people that they have a deranker in their midst, if they have a guy with a 45 next to their name playing with 10s. It would also alleviate a lot of the stress that people had obsessing over a goddamn number next to their name.
Let people have that mark on their public record that says 'this is where I was on my best day, and maybe I took a break from the game, or maybe everybody has caught up to me, but clearly I'm still worth paying attention to in this match'. Then let the background action ensure that they're matched up with people that are currently in their wheelhouse.
