The voice overs are a shame, but not game killing. I agree that it could be a good idea to make a fan-made unit icon pack in the style of the "original" Civ 4 icons.
Mechanics-wise I'm sure everything will work out after the next patch.
No I know they're not game-killing; none of the things I listed are except possibly the corporations (and espionage if like me you like Marathon), but my point is, what's the point in official expansions if the quality isn't superior to that of the fan-made mods? OK, mostly, it is, but still, Firaxis were just lazy with many aspects of BtS.