Fire Slug:

As you can see, I didn't do much to it except give it new weaponry, removed the teleporter (Who would want to teleport onto a flaming oxygen-less ship anyway?), augments, and gave it a med bay.
New weapons:
Fire Beam Mk I
Effector Mk I
Augments:
Slug Repair Gel
Internal Effector
I changed the loadout quite a bit. It now has only and effector and a fire beam, but and internal effector to compensate. The fire beam is much more effective at overwhelming the enemy ship with fire, but it doesn't pierce any shield, so you instead have to rely on the effector to hack their shield system. It now seems much more balanced than what it was before. I also threw in a level 2 sensors just for kicks, because it's more fun to actually see the enemies burning in their ships.
Download: http://www.mediafire.com/download/6sz4g ... 282%29.ftl
Old Version download: http://www.mediafire.com/download/pj06w ... ruiser.ftl
I just uploaded this for fun, but if you think it's overpowered let me know because I want this to be pretty balanced.