A couple of quick questions answered for Strike Leader (SL):

Will every Rogue Hammer army list get a SL version?

Yes.

Will every Rogue Hammer unit be in SL?

That's the plan as a starting point. Now, there are a couple of cases where there are "variants" of a single unit in Rogue Hammer, to reflect different weapons load outs, like the Star Knight heavy weapons for example. In that case, I may pull them back together in Strike Leader. 

Will SL be split into two or three books like Rogue Hammer?

At some point yes, since the page count will be hard to manage down the road. It will work the same way as for Rogue Hammer where your download will just contain two PDFs: One for the rules and one for the army information.

Will every unit be provided for free?

That part I am not sure about yet. Since SL unit entries are larger, I don't think having an army book that is 600+ pages is going to work all that well. Also I want to do all of this, but I can't commit to what is essentially writing 20 Codex books for free, obviously :)

What I think will happen is that the core rules will have the basic version of each army with a handful of units for each army. so the game is fully playable in itself. Then once those are all done, I will probably do some sort of army books. Or maybe it will be booklets with a collection of themed units. I am not sure. We will see how it all goes.

Will there be more fluff text?

We have had a ton of fun creating the fluff pages. I am planning 1 per army for now. If there is any interest, I may do more down the road as well.