Well, I could've been sleeping, but I just had to try this out. Congratulations on an amazing and original mod.
I only playtested this against Vanilla ships, mostly in the simulator but also one random battle. During that battle I used Vanilla ships (and outnumbered the ICE fleet); during simulation I tried out all the ICE vessels against whatever was the most amusing at the time. I don't have much practice with giving feedback, but here goes.
Possible bug:
When the Voidreaver appears in battle, the box indicating whether it's a friend or enemy is tiny. I'd guess that's a ship radius problem.
Love it's main cannon, by the way. It makes enemies go flying, and also kills Buffaloes in one shot. The ordinance deflection is kind of weird, but most of the time it's not noticeable. I only noticed its effects when I re-watched MesoTroniK's video and saw it push away the Exiegency's torpedoes.
Generally speaking, I feel like your armor values on Destroyer and larger ships are too high. I had an interesting duel between a Kelpie and a Hammerhead with Assault Chainguns, for instance, and with regeneration the Kelpie effectively had infinite armor. I think it took 8 hull damage overall, only from the explosion?
Generally, the armor is completely insufficient against deadly, single-shot high explosives, but it's quite a problem otherwise.
Yes a Kelpie can fit the front of an Onslaught in it's 'mouth', but it's still suicide. Had to try it out.
The Kelpie keeps getting its tractor beam disabled. That might not be a bad thing, but I'll mention it just in case.
Your large energy weapons might do too much damage. The awesome Mobeus Beam seems to be a generally easy choice since it can hit fighters, missiles, and even usually bounce over shields, and it's pretty good at all of the above. 2 Fission Beams melted a Hammerhead in around 2 seconds once shields were breached.
I think the Athame would be better off if it's default loadout had Reinforced Bulkheads and Blast Doors instead of armor, since all its armor melts off once it collides with anything anyway. I also tried putting a Front Shield Generator on it; I have no idea what that would do to the AI, but from a piloting perspective it can help the Athame not die to missiles.
You have a medium missile bomb weapon that isn't on any default ship weapon; I forgot what it's called. It was pretty fun on the Flashghast, although I couldn't tell if the Buffalo exploded because I rammed into it or because the bomb hit.
I don't really have detailed feedback on individual ships aside from that. Take what you'd like. Now, I want to see how they fare against Blackrock. Once again, thanks for sharing this with us!