These are some great ideas, especially the simple ones like bringing a garbage bag. That’s something so easy and cheap that it’s easy to forget entirely, but as you say, it can make a huge difference in the right circumstances. It’s also good that you discuss some minor bike repairs. That’s another thing that can salvage or destroy your ride. You want to be as prepared as possible for the best possible experience.
This gentleman is a true professional!! He is an ex-Marine and I will tell you that he represents them well. He is honest, knowledgeable and extremely reasonable. He repaired my son's bike while I waited and went over the whole bike and made the required adjustments replaced an inner tube and all for 20 dollars!!All the kids in the area pass by and call him by his first name. I will recommend him to everyone I know since there are very little of them out there!!
Every person who considers themselves a cycling enthusiast should know how to do at least some basic bike repairs. This is not just to satisfy an unwritten standard of being a bikehead, but because it has a lot of practical implications as well. It can make the difference between dealing with a minor issue quickly on your own or waiting a couple of days for a busy mechanic to squeeze you in. Moreover, in the long run, doing the dirty work yourself will save you a lot of money.
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.