Ben
I agree with much that you say.
The place to get familiar with the handling of a bike (let alone one loaded up luggage) is not even on an overnighter, it should be in a "no stress" situation where time is not a factor.
It's better to go on short rides (day, 1/2 day, few hours...), where it doesn't matter if you don't get to a destination on time or get worried about getting left behind or holding people up or whatever.
Go and ride the conditions and get used to them. Load the bike up with luggage and see how it feels. Build up to it. Make the mistakes when it doesn't matter.
As far as getting to know each other a riders, the same applies. Shorter rides together where there is nothing other than the ride to think about.
As for ride rules, they need to be reinforced and followed, as your recent Paynes Find weekend shows. I have written about this in the February newsletter, out next week.
pete