Mystic, you'd have to give it two abilities per se, one which is the Unity's "Ship Shove" ability (on their Iconis Guardians) and one which would be the Unity Carrier's "Telekenetic Shove". For realism purposes you aught to make the strikecraft be affected by the explosions more than normal ships. I'm not on the mod team (obviously) but I for one would love to see that in there . Also, would it have to take up an ability slot, or could it just "happen" when the ship dies? (I don't know how buffs/abilities are triggered by the Sins engine).
I've just had a look at the three buffs involved in the two Unity abilities, and I had forgotten that the Guardian abiltity keeps ships at bay while it has antimatter reserves. The telekinetic push, on the other hand, is just throwing fighters away from itself. Essentially, they're close cousins in the ability department. They both have the same effect, but one is persistent and the other is a one-off with damage. We would definitely want to go with the more simple carrier version, especially since it's a one-time effect; just like a warp core explosion.
Concerning strikecraft; it seems realistic that the damage from the explosion should be high enough that any fighters are incinerated, don't you think? After all, there was a ship or two caught in the explosion of the Borg Cube in First Contact, and they didn't make it.
I've messed around with the explosion files a bit, but as far as I know there's no way to apply an actual modifer like an impulse or damage without it being a buff.