Good work TDC. You've figured out some of the stuff that was stumping us when a few of us were playing around with this. Getting the damage model to work is sweet.
The one thing I do remember is about the textures. It seems that when using DAT files SH5 won't render the specular or diffuse maps that are part of the dat files and part of sh4's rendering engine. That's why the ships all seems to be one "brightness" in sh5. In sh4 the engine would use these maps and it really makes a difference when they are used. If you were to remove them and go back into sh4 I believe they give you the same look that you get in sh5.
I hope this makes sense. If I had more time in my days I'd put more time into this. Maybe I'll be able to, life likes to toss me around the spinner all the time.
And for a good example what i mean with the textures here's the Yamamoto in SH5 I did months ago. It doesn't look the same in sh5 than in sh4 because of the specular/diffuse maps not being used. I don't have a sh4 screenie but you all get the idea.
It doesn't have guns but meh. That's small potatoes to add