Our apologies, our battle armor experts were detained by airport security. Do you know how long it takes to strip search a Grenadier?
Has every trooper 2 shots? In RS:3058 Clans Unabridged are two "dots" per trooper.
Yes, every trooper has two shots.
Can more than one trooper deploy minefields and increase the size? 2 trooper = 20; 3 trooper = 30...
No, you can only deploy mines with one trooper per turn, see TO (second printing) page 325 "Only one trooper per battle armor unit (Squad, Point, or Level I) may deploy mines each turn."
How much BV do you pay for the different types of mines?
BV for different types of mines can be found in TO at page 385
Can you mix different types of mines within a squad?
No, every trooper has to carry the same type of mine, as per the rules that you have to carry the same type of missile ammunition for every trooper.