From what I understand, there was no truncation of the Shadow War due to Cancellation fears. I believe, only the final four of S4 (Not including Deconstruction of Falling Stars
) were truncated, they were meant to stretch out into the first couple/few episodes of S5. On the flipside, Byron and his people would've started flowing in, in the background at the end of S4, so there would've been a smoother transitition between Seasons/Plot lines. Then of course, there is Ivanova's originally intended S5 Arc.
Putting those things back, is about all I'd change and I wouldn't want to lose Deconstruction of Falling Stars
, I know some don't like it, but, many of us like it quite a bit.