A few of you have picked up on shifts between US and British spelling conventions. This will be a challange because different publishers previously sorted that out for me. I will probably go with the US spelling, simply because I sell more books there and it would save me a lot of extra work preparing additional manuscripts.
The question of ass and arse, however, is less problematic. The various characters will use which ever version is appropriate to their native dialect. That mostly means Emmeline will say arse and everyone else will say ass.
As I resolve the various queries, Google docs deletes the notes. But some I'm leaving there with my own replies to your questions. Eventually they'll go too, but I'll leave that until the last minute so you can see my reasoning for various decisions.