8) Heavy's food items can be thrown using right click, The sandwich and steak acts as a medium health pack(50% hp) , and the chocolate bar serves as a small health pack(around 20.5% hp) . This can potentially save someone's life! (Especially your Medic)
9) Engineer is the shortest class and heavy is the tallest
10) Every class moves at a different speed, Scout moves at 133%, Spy and Medic moves at 107% , Pyro, Engineer and Sniper moves at 100% , Demoman moves at 93% , Soldier moves at 80% and finally, Heavy moves at 77% ... Running backwards reduces your speed by around 10% (Scout would run at 120% when going backwards) Crouching reduces it to 33% (Scout would crouch walk at 44% ) 
11) Projectiles like rockets comes out from where your viewmodel is currently at! (Exp: If your viewmodel is on the right, the rocket comes out from the right, if in the middle like The Original, it will come out of the middle)
12) Sentry rocket's damage ramp up is based on how close the engineer is to the target, not how close the sentry is!

Correction from last raffle: "Afterburn will reduce a medic's healing down to a 25%! (Vaccinator's shield resist is also reduced by 25%) ."  New answer: https://www.youtube.com/watch?v=oYfx64j3BGc 

Blue = Positive Effects
Red = Negative effects
Green = Healing/Ammo
Orange = Extra damage like mini-crits
Violet = Important Stuff!