However i am not overly concerned about my living situation: i have a backpack's worth of possessions, and the past 3 years have been a mix of staying at my (now ex) girlfriend's, either parents, or even my car!

What you expect Seller to do before settlement, 5 Possession terms, 6.

Then you have a closing date which is the date you take possession of the property.

If she always pays on the 5th, she probably sent the letter on the 5th,  so whatever date is on the letter shows when it left her possession and I'd assume that to be when you can charge the late fee, not when you receive it, just my opinion-- but again-- don't do checks! 

As there is no equity, they are very likely to do that.You may need to explore further options if he filed Chapter 13.Either way make sure you pursue your options to collect as much as you can from the court, although with a Chapter 7, that's likely to be near zero.With possession, you can start collecting rent.

That said some creative stuff would be not just owner financing but a delayed settlement or a delayed settlement with immediate possession, a master lease option, a plain option to buy or some combination of these techniques. 

Have your pre-approval or proof-of-funds dialed in and never leave home without a blank check in your possession.  

I knew i wanted my writ of possession so I ASKED IF I WAS getting it.  

I just got possession on a property in Campbell River. 

I would take possession of property and pay them directly.