Well just woke up after sleeping poorly, lets see if I can reply competently.
*Watches closely* 
Can't beat me. I am always watching.
Yeah, I meant for Dwarves. Once Toady puts Dwarven mounts back in the game (at some point, probably not too soon) vehicles will make a lot more sense. Also, could you make them shoot some kind of rock that explodes? I'm sure it would be Dwarvenly unstable.
And yeah, I'm glad I'm still here. Last time I dived into the raws, I didn't do anything else for five days. Except what was necessary, you know. But contributing to the forum gives me something to keep me tied to life.
Huh. Didn't know that, but it would be interesting.
Armor piercing rounds, explosive rounds, incinderary ammo, tracer rounds (emitts a little light material is a little hotter)
Possible. I already have the format for explosives, and I know of several weapons that use different kinds of ammo. It would be interesting to see the advantages and disadvantages of each ammo, like the heavier armor piercing round being slower but heavier, or making the explosive rounds slower etc. Great idea.
IR goggles,
On the list, but not possible until next version.
parachute
I can think of a way to do this, and a parachute like effect is possible. But at the moment, only goblins have flying things and they rarely ride them. Maybe next version when they fix the flying glitch that makes it so you can't fly in fortress, until then my workaround wouldn't work for dwarves.
Concision grenade, flashbang, smoke grenade, emp grenade,
All technically possible, but like the other ammo you suggested they would probably have to be fired by a rocket launcher (probably a new one. Right now the only rocket launcher is the Armbrust, which is strictly an anti-tank weapon. I used it because the name means "crossbow", nice little bit of trivia. I also misspelled it in the raws, but nobody will notice)
Though it does bring the question "Why would you want to leave your enemies alive?"
claymore/bouncing betty (immobil creature that explodes when enemies approach)
We already have the anti-person mine, which is a little more generic. It is instead a trap component, that blows up when someone steps on it like the rockets do.
sentry turret, uav (small flying creature with a high sight radius), assalt drone
Possible. But in the next version, right now creatures can't fly in fortress mode.
emergency squad support (timed 1 use summon)
Don't know what you mean by this.
riot shield
Probably when I get back to armor. Shields are the only thing that can block anything with the high velocities we are working with.
gun attatchments (gun + item = modded gun (may take awhile to make all combinations))
Possible....But it would take an obscene amount of time to make all the combinations. Maybe at another point in time when I have an obscene amount of free time again.
camo armor/guns for flavor and variety,
Possible, once again once I get back on the armor. Until then you will have to deal with normal vanilla Kevlar breastplates and shields. Tanks are probably better armor at the moment, anyway.
gas mask.
Interesting. Maybe possible (Gives a syndrome that temporarily gives the dwarf [NOBREATH]? That would make it immune to inhaled syndromes for a while). But I wont need it until I get the bombers to the goblins.
To balance more advanced stuff you could make them require more materials/next tier workshop.
A good balancing thing. Expensive and strong or cheap and weak? Though what I give to the goblins won't have that weakness...
Can you set how long it takes to make something or make it require a certain skill level?
Probably. Beyond my skill. Still only having done this for less then a month.
I'll try to think of some civ stuff. If you get the electricity thing in there lamps, tv, radio, running water and so on. Mabey you could make a workshop Electric Generator as a custom workshop then make electric parts there and craft that stuff some where else at least untill you make up a better way (did I explain that right?)
Like I said, civilian stuff is the hard part.
I got electricity up, though I would have to find a purpose for lamps, tv, radios, and running water. I have a workshop that uses petroleum to make capacitors (Which carry electricity). I could make different workshops (Like TV factory) to make parts if necessary.
P.S. Typing on a phone is annoying and sorry for the wall of text. 
Walls of text are good. They bump my post and give me ideas.
Tazers and their gun variety.
Possible. But why would you not want to kill something? Syndromes can give pain and knock things out real easily.
ou could add handhelds as toys and arcade cabinets/consoles as 1x1workshops to raise room value!
That was the original intent of the computer. Then I figured out I have no clue how to do this. I will ask someone and see if this is possible...
But make it so you need a tv to gey dvd/bluray/console/cable and so forth and from those you can get thier remotes and accessories (may take alot of time/tweaking)
Well if I already have a workshop, making toys that do things and get remade is possible. For example, I could have the TV take one DVD player and in the reaction give a DVD player as a result, not using up the player as a result. But I would have to make it do something...
I know a mod that has an artifact case that raises in value the more artifacts you use, at least I think that is what it does, if that is what you are getting at.
Also their could be snack/drink dispensers. More foods/drinks could be added
You would have to put snacks in first. Kind of defeats the point of it? Though I have thought about adding new food, like fastfood.
You might have to make an item to represent currency for some of these (or can you already do that with default cash?)
I could technically do that with existing cash, but then one must wonder where the food comes from...
More modern toys as well be it sports , board games or action figures. Well I should get some sleep! Hope some of these ideas help. I'd love to help as well as dip into modding but I just don't have enough time... 
The toys would be easy to add, and I might do that later.
Thanks for the ideas! Lot of em here.