It might look rude but it shows Jirou being serious getting a proper job so they can live together. They both regretted immediately and want to apologize. Thats a couple development.
The story could have ended already but publishers often push authors to stretch the stories if they are popular. I'm getting the feeling here, the pace somehow slowed down for no reason
True, unless there is very specific use of "mister/miss" in jp raws like in Reign of Seven Spellblades. It's even in the anime and it sounds really out of place.
https://animestuff.me/docs/assets/html/Villager-A-Wants-to-Save-the-Villainess-no-Matter-What.html this chapter is in the beginning of 2nd volume. Careful, you need to go through Linkvertise to download.
The group that translated this novel doesn't exist anymore and their website is down too, but remember reading it some years ago and it was pure adventure with zero hints of romance with just small gags here and there. Might be wrong though I don't remember clearly.