I’ll agree that Halo 4 is actually similar to CoD, though your list is hardly what makes it so.
1. Weapon Skins
Weapon skins are purely aesthetic, and have no influence over gameplay whatsoever. Beyond this, CoD is hardly the only game that utilizes weapon skins. This is a moot point.
2. Perks
Again, CoD isn’t the only game to utilize perks, they’re actually a very common gameplay feature. Nevertheless, I can see where you’re coming from, and in this instance Halo 4 did indeed get its perk feature from CoD. That said, the perks are quite tame in Halo 4; they’re more akin to convenient bonuses like extra ammo, instead of game changers like Stopping Power.
Still, I’ll give this one to you.
3. 9 vs. 9 (BTB)
BTB has always been a staple of the Halo series. You could just as easily say that Halo is taking a page out of Battlefield, because BF is known for its large maps. What I’m getting at is one did not influence the other.
4. Points instead of kills
Much like perks, points instead of kills is a very common feature, and CoD certainly isn’t defined by this feature. The shift from kills to points was strictly to help balance out gameplay (you are now properly rewarded for getting an Overkill, for example), and its similarity to CoD is purely coincidental.
5. Copy and paste perks from CoD. For example, Dexterity = Sleight of Hand.
This one is… Inconclusive. On one hand, yes, Dexterity is essentially just Sleight of Hand. On the other hand, this similarity could have been a simple lack of originality; there are very few bonuses out there that won’t outright break the game, and thus 343i’s hand may have been forced.
6. Ordnance Drops (Care Packages in CoD)
This is another one that I’ll give to you. Ordnance Drops are, at their core, CoD’s killstreaks (albeit not nearly as powerful). The basic idea is identical: You get enough points, and the game rewards you with power. Of course, Halo rewards you with its iconic power weapons in lieu of CoD’s air support.
7. Fully customizable Loadouts
This is another one that I’ll have to call “inconclusive”.
Of course, CoD is very well known for its custom loadouts. They add that extra bit of flavor to the game by letting you play how you want to play.
That said, you have to consider the fact that any custom loadout builder will be similar to CoD, on the principal that CoD’s builder gives a lot of freedom. “Weapons” and “Perks” are about all will get with any game that offers custom loadouts. You could just as easily say that Mass Effect 3 took a page from CoD wit its custom classes. Of course, you would be wrong; CoD had no influence on ME3 whatsoever, but the resemblance is still uncanny: Select a weapon, give it attachments, choose your perks.
—My own little rant—
Halo 4 is quite similar to CoD, but the similarity comes from its core gameplay. Halo 4 is considerably more “casual-friendly” than previous titles, and this was by design. The game was intentionally made inconsistent and easy to play so that everyone can have a chance at reaching the top of the scoreboard. In Halo 3 I was an average player, but my scores would be consistently average. In Halo 4 I could go 30/3 (kills/deaths) in one match, and then go 4/11 the next. There’s no underline reason for this, it’s just how 343i made the game. The line that separates good players from bad players was blurred in order to attract a broader spectrum of players.
The game also nearly got rid of Halo’s well established aggressive gameplay in favor of defensive gameplay; you’ll notice an increasingly popular tactic (especially in BTB) is to simply lock down an easily defended location and let the kills come to you. There’s no penalty to doing this, in fact everything down to map design encourages it.
It’s this catering to casual players that gives Halo 4 the “CoD feel”. Weapon skins and perks are not responsible. The game guarantees that you will have your moment to shine at the top of the scoreboard, whether you really earned it or not.