Last I heard, the PS4 version's "first episode" is planned to be Books1+2 together (for a "meaty" first impression of the series). And yes, Sony requires that an episodic series to be sold per episode (not only the whole season), but Book 1 will always be compiled with Book 2. Books 3,4 and 5 will be sold separately though.
Ah, yes, this sounds familiar, now that you say it
And all my previous posts may be a result from reading this post by Morten
Porting it to PS4 means having to utilize Unity 5, and when we do that and release the game for PS4, I can't see any reason why we wouldn't want to utilize Unity 5 for the PC versions too. It might not be at the exact same time, since there may be different requirements and limitations, but creating a PS4 version with Unity 5 and then not moving to Unity 5 for PC at all is not something I can see happening.