I think you guys are missing the point on the collision, he means as in they'll interact with the ship as in exchange of kinetic energy/motion, instead of just being a standard projectile that dissipates the moments it touches the enemy ship. Which personally, cannot be done atm. You can get a projectile with the appearance of an asteroid, but none of the ingame 'asteroid collision' properties.
Beams can't be modified to fire in bursts (more than one beam in a click), and their accuracy can't be tampered with.
I think what he wants is not a beam weapon, but an energy weapon. Beams aren't what you want if you're making a laser weapon.
And you can make weapons more innacurate the longer they're fired. I suggest taking a look at this page on the modding wiki.
http://starfarer.thegamewiki.com/wiki/Weapon_Data_CSVSpecifically, these lines are what you're looking for.
min spread - The minimum angle (in degrees) that projectiles will be constrained to firing within. 0 means that the weapon fire can be perfectly accurate, but may not be due to other factors such as max spread.
max spread - The maximum angle (in degrees) that projectiles will be constrained to firing within. 0 means that the weapon will fire shots with perfect accuracy. A maximum spread of 30 means that fire will be wildly inaccurate outside of point blank range.
spread/shot - How many degrees of spread, per shot, is added to the onto minimum spread. When the maximum spread value is reached, there will be no more continued accuracy reduction. Thus, firing a weapon for an extended period of time could make it less accurate. Without a spread/shot value, a weapon will always fire at its minimum spread value.
spread decay/sec - How many degrees of spread are subtracted, per second, from the weapon's current spread. This value is used to control how quickly a weapon will return to true minimum spread after you stop firing.
