There are different weapon types yes, you can see this more evidently when you look in the tech trees for each race.  You can tech certain weapon types which helps different ships, the tooltip for the tech tells you which ships use that tech type.  In the case of Cap ships they normally have multiple weapon types.

Cap Ships tend to have different amount of weapon types on different parts of the ship (front/side/back).  What isn't clear without a bit of outside game research is how much of a cap ships damage is distributed to different weapon types.  For example the Volkuras Desolator has most of it's damage as phase missiles but it does use wave cannon and possibly the vasari beam weapon tech, can't remember exactly.  Whereas the Kortul Devastator has much more of it's damage as wave cannon and beam damage.

The different weapon types are only really different based on their tech trees, phase missiles being able to ignore shields being a very distinct example.  As far as I'm aware there are no range differences specific to weapon types, only specific to ship types.

remagen,   well dfifferent ATTACK type's do exist,   there are no different weaopon types however,  

you should rather think of them as different ship types,   for example,   Flak frigates use ammunution and are meant to kil fighters (tough theyre not balanced yet.. and u shouldnt build em even to kil fighters)

Kodiak heavy cruisers also use Ammunution , however they use far larger rounds and are meant to kil any ship type (except squads)

both the flak and kodiak use ammunution wich doesnt affect their weaopon strenght,  but determines wich ships wil get upgrades,   if youfor example,  upgrade TEC armor,  ofcourse, every ship will benefit for that,  becuase every ship uses armor plating,      if you upgrade TEC ammunution  not every ship will benefit, only the types that actually use ammuntion...  good example is upgrading ammunution if you only have Cobalt light frigates,   you can consider that useless (becuase cobalt frigates use lasers) 

so... yes  different weaopon types exist,   but llike your exampel concerning lasers and blasters   the kol's Lasers shoot forward only,   it's "blasters"  shoot sideways only , all weaopons on the koll SHARE THE SAME RANGE,   the only thing u'll have to worry about is to get the kol in the middle of the battle, making all sides fire and not letting it die...

other then attack types there not much differenance... tough there's an "armor" and "damage reduction sytem" 

u can find these on the forums.. or google it..

What about Radiance ability to eat energy weapons? 

You mean any damage types will convert into AM?

Yes they are autocanons,

Anything that isn't a bullet, missile, phase missile, or gauss round will add AM.