I have written some other guides on X2: The Threat. I will link to them here.
https://steamproxy.com/sharedfiles/filedetails/?id=1369777561https://steamproxy.com/sharedfiles/filedetails/?id=2088317556

The Kha'ak are bad news. When they first show up, they completely wipe out President's End in a cutscene. This is not an exaggeration of their abilities in actual gameplay. All Kha'ak ships are very dangerous for their class, they always appear in numbers, and since they have point-to-point jumpdrives, they can appear anywhere, at anytime. Fortunately, the normal Kha'ak raids that occur regularly are much smaller than the plot-related ones. Kha'ak fighters have the curious ability to attach to each other to form large clusters. Generally a raiding party will consist of one of these clusters, which will seek out a target and split into its constituent fighters upon making contact. A good tactic if you spot a cluster early is to close with the cluster as quickly as possible and hit it with PSGs before the cluster has a chance to disperse.
In summary:

• Field fast and deadly ships in large numbers.
  
• All ships mount Kyon Emitters exclusively.
  
• Raiding parties can appear anywhere at anytime.
  
• Out to kill everyone else.
  
• When fighting them, PSGs or Ion disruptors are best.

Some notes on Kyon Emitters:
Kyon Emitters are probably the deadliest weapon in X2: the Threat. Though they cannot match the PSG's capacity for rapid destruction over a wide area, in precision strikes they have no equal. They have an exceptionally long range, outranging all other weapons except missiles. In addition, they deal damage extremely quickly; even a few Alpha Kyon Emitters can rapidly deplete a fighter's shields. And worst of all, Kyon Emitters are true beam lasers. When a Kyon Emitter is fired, a purple beam instantly strikes whatever the weapon is facing, up to its maximum range. This not only makes it nigh impossible to dodge them, but also makes Kha'ak capital ships theoretically immune to missiles. Therefore, when fighting a Kha'ak ship, always close as quickly as possible, and make sure you are packing the best shields, weapons, and upgrades available.

These are the Kha'ak M5, M4, and M3 fighters. A typical raiding party consists of an M3 backed up by a dozen or so M5s. If captured, they are not particularly useful, since they mount only Kha'ak weapons, which are very difficult to obtain at best. Kha'ak clusters are considered ships themselves and have their own specs, these are not listed here, since the clusters split before engaging regardless. Some pointers on fighting them:

• PSGs and IDs can hit multiple targets at once, and work pretty well against Kha'ak raids.
  
• Generally, prioritize destroying the M3, as it is by far the deadliest member of a raiding party.
  
• It would be unwise to take on a raid in anything less than a fully armed and shielded M3.

Exact specifications for Kha'ak ships are difficult to come by. The only way to obtain this information in game is to get it via a bulletin board post. Said post only appears if you have an extremely positive notoriety score with the station's race. Even capturing Kha'ak ships will not get you access to this information.

Khaak Scout (Class: M5):

Technical Data:
Starting Max Speed: 123.87 m/s
Maximum Upgraded Max Speed: 569 m/s
Acceleration: 38 m/s per second
Starting Steering: 34.99%
Maximum Upgraded Steering: 157.48%
Power Generator: 100 MW
Starting Cargo-bay: 10 units
Maximum Upgraded Cargo-bay: 27 units
Cargo Class: S
Weapons:
1 Forward Mount (Alpha Kyon Emitter)
Missiles: Sting Missile
Shields: 3 x 1 MW
How to acquire: Can be captured if your combat rank is high enough, however Kha'ak pilots almost never bail.

Khaak Interceptor (Class: M4):

Technical Data:
Starting Max Speed: 103.60 m/s
Maximum Upgraded Max Speed: 310 m/s
Acceleration: 20 m/s per second
Starting Steering: 34.99%
Maximum Upgraded Steering: 104.99%
Power Generator: 100 MW
Starting Cargo-bay: 18 units
Maximum Upgraded Cargo-bay: 78 units
Cargo Class: S
Weapons:
2 Forward Mounts (Alpha Kyon Emitter)
Missiles: Sting Missile, Needle Missile
Shields: 2 x 5 MW
How to acquire: Can be captured if your combat rank is high enough, however Kha'ak pilots almost never bail.

Khaak Fighter (Class: M3):

Technical Data:
Starting Max Speed: 90.09 m/s
Maximum Upgraded Max Speed: 198 m/s
Acceleration: 17 m/s per second
Starting Steering: 34.99%
Maximum Upgraded Steering: 104.99%
Power Generator: 200 MW
Starting Cargo-bay: 95 units
Maximum Upgraded Cargo-bay: 150 units
Cargo Class: M
Weapons:
3 Forward Mounts (Alpha and Beta Kyon Emitters)
Missiles: Thorn Missile, Needle Missile, Sting Missile
Shields: 3 x 25 MW
How to acquire: Can be captured if your combat rank is high enough, however Kha'ak pilots almost never bail.

These are the Kha'ak capital ships. You will only encounter these as part of plot-related events or in Kha'ak sectors. They can never be captured, and are extremely deadly. Always avoid fighting them whenever possible. The M2, in particular, can take on just about any other ship and win.

Khaak Carrier (Class: M1)

Technical Data:
Starting Max Speed: 100.00 m/s
Maximum Upgraded Max Speed: ??? m/s
Acceleration: ?? m/s per second
Starting Steering: 4.99%
Maximum Upgraded Steering: ???%
Power Generator: ??? MW
Starting Cargo-bay: 1500 units
Maximum Upgraded Cargo-bay: ??? units
Cargo Class: ?
Weapons:
???
Missiles: ???
Shields: ??? MW
Hangar: 150 M5, M4, or M3. Possibly also TS or TP, however the Kha'ak do not have such ships.
How to acquire: You cannot acquire this ship unless you use the script editor.

Khaak Destroyer (Class: M2):

Technical Data:
Starting Max Speed: 135.13 m/s
Maximum Upgraded Max Speed: ??? m/s
Acceleration: ?? m/s per second
Starting Steering: 5.99%
Maximum Upgraded Steering: ???%
Power Generator: ??? MW
Starting Cargo-bay: 1000 units
Maximum Upgraded Cargo-bay: ??? units
Cargo Class: ?
Weapons:
???
Missiles: ???
Shields: ??? MW
How to acquire: You cannot acquire this ship unless you use the script editor.

Here's another link to the first part of the guide, where most of the other stuff is.
https://steamproxy.com/sharedfiles/filedetails/?id=1369777561