I hope this isn't too late in the process.
I was a big fan of custom races in the MOO series.
I'm fairly sure this feature was in MOO2 and I think it'd be fairly easy to implement.

Given GalCiv2 has so many customisable attributes.
It would be great, if there could be negative attributes included to obtain more ability points.

I.e. Research ability -10% research, + 1 ability point.
or
Economics - 10% economy, +1 ability point.
etc.

It doesn't need to be a huge negative tree, for super horrendous attributes, but the ability to gain more then 10 ability points would make the races infinitely more customisable.