I have used Rosiver for a few months now so I will answer some of your questions (hello fellow Canadian!)

1. I used Finacea with Rosiver (Finacea AM, Rosiver night) but found that the Finacea was doing nothing so I discontinued. I now use Metrogel AM and Rosiver at night
2. Yes if demodex mites are causing inflammation and rosacea acne, the Rosiver will help
3. I apply Rosiver as a moisturizer since it's basically a cream - it's not an acid like Finacea (azelaic acid) nor is it like Retin-A or something strong like that - you never feel it - it's also quite rich so for me I don't need a second moisturizer
4. I have not experienced a die off period - just a gradual reduction in redness. I did get some small zits between my eyebrows but that's because the base for Rosiver is so rich and I don't typically use rich creams - these zits have stopped appearing
5. Theoretically the demodex mites can come back so most people use Rosiver nightly for a few months and then once or twice a week for maintenance.

I hope this helps!!