So by anolyzing the trailer multiple times I think I figured out how this new system is going to work!

There are over 50 weapons and over 700 modifications in the game so there are plenty of crazy things that we don't know yet!

<> Frame/Capcitor/Reciever: Reciever (Guns)- So guns have a Reciever which determines if it's semi auto, automatic,eta it may also have something to do with the cailber of the rounds it uses!
Capcitor (Energy Weapons)- this could change the behavior of your laser rifle altogther, As far as we know maybe make different types of energy weapons out of a laser weapon. We don't have information quite yet!
Known Mods- Heavy Frame, Automatic Reciever, Photon Exciter!

<> Barrel- The barrel seems to add to attributes and subtract from them too. What I find very interesting is that the Plasma Rifle became a Scatter gun and a Plasma thrower and lastly a Plasma Thrower (Flamer Barrel) So it seems that some barrels may change the weapon altogether!
Known Mods- Assault Barrel, Short Ported Barrel, Sniper Barrel, Flamer Barrel!

<> Muzzle- To reduce recoild or add effects! Seems you can add Bayonets, Supressers, Compensators, Crazy weapon transform upgrades (Ignition Module, Electrocution Module)

<> Magazine- Ammo capacity but add weight?

<> Scope/Sights- Add zoom, accuracy!

<> Grip/Stock- Determines if weapon is rifle or pistol variant! Reduce recoil! Less AP Cost?

<> Misc Upgrades- Material, Baseball Bat Razors, Nails, Barded Wire, Saw Blades, Eta, maybe paint or camo!

Easy there, dude, you forgot to the mention the "Tiered" mods that factor into this, meaning that '700' modfications is really around "150-200". Just saying.

Tiered or not, 700 is still a impressive number, especially if we compare to NV.

It's not really impressive when you consider them tiered, which means most of the weapon mods is just added fluff. Bigger doesn't mean better, honestly, especially when you begin to start picking the mods apart. Now if all 700 were actually unique modications and not actually tiered fluff-bullcrap that's actually over-inflating the numbers, then call me impressed.

To be fair since it looks like tiered mods have unique models (such as pistol grips, etc) you can at least argue we get some creative freedom to design our guns, plus unlike NV this time we get mods that quite radically change how the guns operate, unlike NV where it was just pure stat changing.

Those unique models will mostly all look the same I'll bet. SMG muzzles and barrels will just be extensions modeled and textured to match the gun. Good to have, but not exciting. Unless they're unique and made from bizarre parts that actually show on the weapon, then I'll be impressed. As said above, they're just really all numbers.

In fact, If there's 5 tiers of weapon mods, and they count as part of the 700, then 700/5=140 actual mods/50 weapons=2.8 mods per weapon, meaning most of the weapon's will have 3 weapons, whereas only a few weapontypes will have just 2 before placing something will radically change it into another weapon. For all we know, 50 weapons means the Pistol and then the automatic pistol/SMG. I mean wasn't one part of the videos show a handgun turn into a laser rifle at one point?

Todd Howard said over 50 base weapons.... as in pre-modifications.

yet we built a laser rifle from a handgun. What? Also don't believe what Todd says all the time, as stated within the story threads.

As far as I can tell, there are only two tiers for some of the weapon parts. There were regular and improved versions.

That is the mods added, which doesn't change the amount of base weapons in the game... it is just a result of the modification mechanic...

I also noticed some models look identical like the standard grip, comfort grip, tactical grip. But this maybe due to these grips working with other pistol weapons like the laser pistol and 10mm, plasma pistol!

Still, we have seen a nice tease of what those numbers mean in the enf, and it is looking quite good.

Well Assualt barrel works on the plasma rifle and laser rifle as well as the pipe rifle. So this confirms that they'll be a lot of mods that work with other base weapons!

I'm sure there will be unique mods too though

This does not match that we see in any way. we saw him modify an laser pistol and a baseball bat with lots of parts. the simple rifle also had lots of modifications.

I have problem understanding that you think of as tires. Yes your crafting level matter, you will not be able to make the more advanced stuff without perks(skills) This is one tire.

You are also likely to have stupid names on some items, your mentioned advanced beam splitter, who is likely to be better than the standard spliter. This is another tire, note that the improved versions might also have downsides, increased weight is an obvious one, an receiver for increased rate of fire is likely to reduce accuracy.

With 700 I think this is the number of parts for weapon modifications, some are of the simple advanced or high precision others change the functionality a lot.

Far from all parts can be used on all weapons. Unique weapon types like the rock it launcher or more special weapons like an fatman or gatling has unique improvements however can not use many of the common ones.