I don't think there's anything wrong with the alternate dimension stuff. It works, there's precedent in other mods, and perfectly within the expected capabilities of what we assume to be Type III+ civilizations.
You're messing with dimensions every time you subspace jump anyway.
Fair enough, I just don't like it. Also, it is implied that although on par with Vishnans in every other area, the Shivans aren't all-dimensional and powerful which isn't right.
By the way, I went to the retail campaign, to try it out with media vp's and all that nice shine, also knowing what I know now from BP. GTVA seems to be dead on, as far as their tendencies and behaviour. Just looking at their excursion to Gamma Draconis and agressive handling of that situation, the attack on UEF makes that much more sense.
On another topic completely, I often wondered if the Destroyers' motives are somewhat connected to the fragile relationship and slightly disfunctional and artificial alliance between Terrans and Vasudans. Thinking about it-between Neo Terra, racist remarks all around, Vasudans' superiority complex and difference in basic direction in which the species are heading ( one is dreaming about home, the other is creating another home), it seems that Shivans are the only thing keeping the allies together. Excluding preservers and destroyers, when a generation switch happens and there are no living survivors of the second incursion, a new war seems a high possibility, which then brings the Destroyers back into the fold. Their assesment of Terrans of destroyers is exactly correct by the way, both historically and in FS continuum.