1: projectrho
2: assuming no handwavium drives, engagement range is always the outer edge of the plane between the targeting system's minimum precision and maximum traverse rate, shot travel time and ability versus the opponent's ability to react and evade said shot.
3: they've been carrying beef for centuries? Their grandkids will be the ones to do the fighting.
Lasers can reach the furthest with minimal ability to anticipate an attack (lasers can be seen preparing to fire, like aiming, dust covers retracting, etc.), but kinetic weapons bring more pain if you can get close enough. Getting close is difficult if there is no FTL, since you and your bullets / missiles can be spotted and plotted well in advance of your arrival.