My story is very similar to yours and I'm landing this week. Don't give much energy to the fearmongering because it'll only make the process more stressful than it needs to be. Definitely take many pics and even save emails and IM chats. Photos of you with her family are icing on the cake. Create a pile you can keep adding to so once you're married and living in Canada (as a visitor) and ready to apply, it'll be easier. Add dates, descriptions and identify people in the photos. Come back here with any questions - there will be many!
I consulted with a local organization for newcomers to Canada and they helped me quite a bit. Check to see if there's anything local where you'll be living.
As far as entering Canada, I always simply said I was visiting friends - I highly doubt it will come back to haunt you.
Best of luck to you!!