Yes fair enough. I couldn't link mine initially because when I started they only did linking in the US. It does get confused IME by UK/European style overdrafts. I have done something about this with a dummy account and somehow it works, even though it's linked.
For whether to roll over money in categories, I used to use emojis on the end of a category name to denote what would happen to the money. I still have them on a couple but most of the time I know what I'm doing with each.
🔒 = don't borrow/steal money from this category (used for personal categories, like pocket money)
💰 = let this build up over time, top up by the stated amount
🚧 = max amount to let this category build up to, don't keep topping up if it gets that high
You could also use ↩️ for categories to reset to 0 at the end of a month.
For fixed bills that come out on a specific date, I use spaces to line them up (the spaces don't work on MN) and then the date so something like
💡Electricity - 22nd
For yearly ones I do the month so stuff like
🌳YNAB - May
Then I rearrange them all in the master category so I can see what's coming up next.