The main thing I noticed is the mention of this character Lord Tristan of House Gisoreux, which I assume to be a reference to the character of the same name from Warhammer. I am currently at work and do not have access to my lorebook, so I could be wrong but I am uncertain that any noble houses beyond the current four are extant. I caution against inventing new houses if you wish to remain truly air-tight with the lore.

I applaud the amount of work you put in to writing the background story though, it was an enjoyable read.