1) type; this addweapon nameofweapon. You will also need to add magazines; this addmagazine nameofmagazine. If you want the weapon loaded when you start, add magazines before you add your weapon.
2) I'll assume you didnt understand the BAS readme file regarding HD Magazines. So here is a brief explanation, HD stands for High Dispersion. This makes the weapons using these magazines less accurate, allowing longer fire fights.
-Mr. Sert