How Realistic are TF2's Weapons?

I've always been interested in TF2's weapon design and how they COULD work in real life.
Although good luck having the patience and money to build a fully working Scattergun.
I've taken all the content from a week's worth of shorts and have combined it in this one video. So I guess you could call it a compilation.
I have severely overanalyzed TF2's weapons and probably ticked off multiple angry nerds saying that realism and TF2 don't match (I know that lol).

Let me know if any info is wrong.

== CHAPTERS ==
0:00 Intro
0:22 How does the Scattergun Work?
1:48 Why are Shotguns Small?
2:44 Why are Shotguns and Pistols Left-Handed?
3:26 The Beggar's Bazooka has an Interesting Design...
4:13 How does the Flamethrower Work?
5:30 Could Airblast Work in Real Life?
6:09 How does the Stickybomb Launcher Work?
7:20 How do Demo's Explosives Work?
9:09 How Lethal is a Backstab?
9:55 How does the Sapper Work?
10:44 Outro (End Screen)

== NOTES ==
1. There was a Sniper short I cut out of this video. It was more of a critique of the Sniper Rifle than a overanalyzation of its realism.
2. The Family Business is right-handed but I forgot to include that.

== MEDIA USED ==
=== VIDEOS ===
Videos by Anton Hand:    / @antonhand  
H3VR Devlog: The Guns Of Meat Fortress Pt. 1 - Adapting TF2 Firearms To Virtual Reality:    • H3VR Devlog: The Guns Of Meat Fortress Pt....  
H3VR Devlog: The Guns Of Meat Fortress Pt. 2 - Adapting EVEN MORE TF2 Firearms To Virtual Reality:    • H3VR Devlog: The Guns Of Meat Fortress Pt....  
=== MUSIC ===
Team Fortress 2 Soundtrack | Intruder Alert (MIDI):
   • Team Fortress 2 Soundtrack | Intruder Aler...