Lets start with the Enforcer class Star Frigate:
Quoting SW Technical Commentaries
Manufactured only within the region of influence of the Pentastar Alignment, under post-Endor warlord Grand Moff Ardus Kaine. These vessels were developed from by researchers of KDY and SFS who were left on Kaine's side of the border between the Alignment and the New Republic. It is based on the shell of the SFS Immobiliser-418 interdictor, but the gravity well generators have been removed, while propulsion systems and armaments have been much upgraded.
These cheap vessels were often employed for border patrol, traveling in groups of two, four or sometimes six. The choice of this small patrol ship as a principal component of Kaine's fleet reflects the stringent concerns of efficiency and manufacturing cost with the dwindling of the resource bases of all the rogue-Imperial warlords.
Power output:
At 600 meters long, these vessels are far larger than imperial light ships built before the fall. In fact they are the same length as dreadnaughts, and only slightly smaller than the Acclamator class by 152 meters. Now given the fact that an Interdictor must have an already high power output to accommodate it gravity well projectors.
Here my reasoning:
Since the reactor is internal we can only speculate on its volume. On the Interdictor the only place the reactor could be is between the four gravity generators, that area of the hull has a depth of only 55.5 meters. Assuming the reactor is a sphere with a diameter of 45 meters, its volume is 1,675.5 m^3. Using Dr. Saxton's ISD reactor power output of 1E25W and Darth Wongs ISD reactor diameter of 140 meters (20,525 m^ volume). Which gives an ISD a power/density of 5E20 W/m^3. Assuming the Enforcer has a similar power density (1,675 m^3)(5E20 W/m^3); we get a power output of 8.4E23W as our upper limit. I speculate that the power output should be comparable to a the Acclamator; if not more so due to its more modern design, and lack of empty spaces. So the lower limit of reactor output would be 2E23W.
Shield output:
Again this should be at least as strong as the Accumulators. Especially considering the advances made between the ISD1 and ISD2. IE more efficient design, larger more powerful power cells etc. So, 7E22W (16.6 TT) minimum, possibly as high as 2E23W (47.6 TT) by dividing the reactor output by four.
Sublight Acceleration:
The removal of the gravity well generators and there associated systems from the design, probably reduced the vessel's mass considerably. Which should improve sublight speed, even if more powerful engines were not mounted.
Hyperspace Speed:
This is a true unknown; Heir to the Empire attributes very slow hyperspace velocities to the common interdictor class. While the game Tie fighter credits with a class 2 hyperdrive. However, their is nothing barring more powerful hyperspace motivators from being mounted. The Pentastar Alignment needed to patrol a large volume of space with relatively few vessels, faster vessels would be most useful. Also the vessels would need to chase fast vessels. The ships should also have been built with the realization that they might have to face off against another Warlord's ISD's. So they would be designed to outrun anything they can kill. so, again I'll go with the Acclamators class 0.6 hyperdrive or at the very least a class 1.0.
Weapons:
Official materials credit the Interdictor class with 20 laser cannons, most likely to its support (ie non-combat) role. Just enough to endanger any fighters that penetrate the fleet cap patrols. The Enforcer variant must be much heavier armed given its combat role. Given it size, and without speculating on the actual number of guns. I would credit it with being far more heavily armed than the Acclamators, dreadnaught's, or strike cruisers. The heaviest guns mounted would be medium turbolasers, and at least twice the number of weapons mounted on the Acclamator class transport.
Troops:
The original interdictor is credited with carrying a crew of 2,807, between 24 gunners and 80-1,000 combat troops (depending on the source). It is unlikely that the Enforcer carries so many troops, I would credit them with at most a company sized element (perhaps 200-300 soldiers).
Fighters:
Again, the original interdictor is credited with carrying 2 fighter squadrons. Now given the increased internal volume, after the removal of the gravity well generator and there systems. It should be fairly easy to accommodate 2 or more squadrons with ease. The only problem would be if there were shortages in the number of tie fighters or pilots. The primary hangar bay is 55.5 meters long, while the secondary bay is a tiny 22 meters long by scaling. I'd say 1-2 squadrons are most likely.
Okay, please give me your thoughts, criticisms, wild speculation, etc.