ANY weapons, even normal Meson BLasters and Anti-proton beams, can be made very powerul with the use of Weapon Mounts. On ships of Light Cruiser size or larger, you can choose a weapon mount and increase the power of your weapons. The button for choosing mounts is at the upper right in the ship design window. Use it if you want to survive in combat after the first 50 turns or so.
The "buns of death" sounds like Time Distortion Burst -- it has a special advantage of doing 4 times as much damage to shields as its normal damage rating. It still only does normal damage to your ship, but really burns away those shields in a hurry. This is only available to races with the Temporal Knowledge special ability.
The "Barrels of Ship Capturing" are the Allegiance Subverter, which are only available to races with the Psychic special ability. You didn't see ONE race using both of these, did you? The thing about the Allegiance Subverter is that it is shorter ranged than most beam weapons, and it only fires once per combat. Just stand off at long range and you can avoid it, or use Master Computers instead of crew. Anyway, the AI is usually stupid about using it, and you can send in some lightly-armed decoy to take the hit, and they waste it.