Apparently, saying "well, its halo" as an invalid similarity was irrelevant. Because what you listed there, falls right under that category. I'll explain in the form of a list.
1. Armor abilities? No. First off, there are no armor abilities in halo 4. They are powerups. And the content behind them is nowhere similar to that of reach.
2. DMR. Really? Ok, so using a different example, this is your logic behind this: 'They are bringing the magnum back. So it HAS to be exactly like halo reach!'. I think this may be the most stupid reasoning I have ever heard.
3. Recoil. Again, another idiotic similarity. Recoil has had some sort of effect in every halo game. Excluding halo wars.