New to ARs and want to do some upgrades

[Kinda Bewzy]

5 is a question for Calguns.

[P2000]

First things first, do you have a sling and weaponlight?

[Jellybean]

I am new to the AR world, with so many options and information out there my head spins. I am from commie CA and decided to buy a 16” ddm4v7 mlok with a Romeo 4c and mbus pro. Anyways after a year or so owning my AR, I want to do some upgrades. I also have plenty of ammo before the new law takes affect in 2019.

#1: I want to change the stock to the mft minimalist stock, can I just use the buffer tube/action spring and buffer that I currently have and just replace the stock?
Yes, as long as it's a Milspec sized version. Although I genuinely question what you're going to gain from that stock over either the DD stock it came with or literally anything Magpul if you just *must* change the stock....not exactly what I'd consider an "upgrade".
Since I’m already in there can I just replace the action spring and buffer to an A5 or Super 42 or jp silent g2?
Nope, you need a kit and other equipment as mentioned.

#2: I want to put in a ssa trigger,I’m just using it for plinking not sure if I need it. It’ll be nice to have though. I shot my friends build and the pull does feel nice.
You don't need it, unless you're getting into competition or LR Precision shooting. I've been using GI triggers since I started shooting and never felt *so* held back that I spent money on anything aftermarket. That being said... pretty much anything Geiselle makes kicks ass, and I would not blame anyone for sticking one of their triggers in just for the hell of it...I'd rather have another case of ammo though, specially in CA...
#3: I’ve read many different reviews on anti-walk pins or anti-rotations pins not sure what’s the lingo but if I do replace the trigger should I replace these as well?
No. Unless your pins are that loose, or you're just trying to build the most bomb-proof rifle ever.

#4: this is all cosmetic and I know that but who doesn’t love Iike dressing up their toys? Also it’ll be used to scare my liberal family haha? I want my ddm4v7 to look like the noveske Gen III Infidel Rifle. Would it be just putting their kx3 or kx5 or would I have to get a 16” rail and the kx3/5?
What's wrong with a perfectly good DD-style A2? Is there a legitimate reason you MUST have some sort of directional comp? If so, not sure if Kali legal, but the Surefire Warden + SF muzzle device of your choice is the only one I feel like is worth the bother since you can get the best of both worlds. But frankly, on a 16" barrel, even indoors, a plain ol A2 isn't that "blasty"....why add needless extra weight up front?

#5: not really an upgrade just trying to keep my features, I currently have the fc-hook with the bf-10 and it’s been a pain to load. The bc-10 took time to get use to and from loading I can see pieces of plastic are coming off the bf-10, I don’t want plastic running throw my baby. So I know everyone is up in arms against armaglock but so far they are the only ones that I’ve seen that make a functional reload process. Does anyone have a better solution?
You're gonna need help from a Kali expert there....
Thanks for reading and advice.

Blunt opinion- you have a perfectly good DDM4-V7. There's nothing that needs to be changed there. For the price of all this extra, mostly needless cosmetic stuff, you could have other more useful things...

In that case don't do anything to your AR. You will just lose that much more money when they make you turn it in.

Why the hell would anyone be doing that?