Awesome quality post, rare for these forums. 
One thing I will say, as a Stonewall player we prefer 8.Ne5! instead of 8.0-0, since playing 0-0 first usually gives black two annoying options which are unpleasant for white from a practical standpoint.
- 8...cxd4 and now white is forced to play the ugly 9.cxd4 because otherwise the f4 pawn would be hanging. This is a pawn structure white should avoid
- 8...Ng4 isn't possible in this position because of 9.Bxh7+, but is often a good reply since after 9.Qe2 f5 white's kingside attack basically doesn't exist anymore.
In general I would say that white should pretty much always play Ne5 before castling in the Stonewall, and there are very few exceptions.
Hi all, here I present ten white opening systems that you can play against anything that black plays:
1. The Barcza System
2. Bird-Larsen Attack