I have done several supported tours, some long mileage days / camping and at least one leisure, short mileage / motel type. In both cases a whole bunch of very colorful looking aliens decent on some or many little towns in the middle of some beautiful part of the country. All the riders stay in their alien pods and move in mass. So I suggest the following;
1. Leave the loud crazy jerseys at home and wear as close to normal cloths as possible. You will have a better chance of meeting the locals.
2. Get a good set of maps for your route so that (If the daily mileage is short) you can explore off route and away from the alien pods. Leave early and arrive late so that you can explore as much as possible.
3. Yes a lawn chair (folding chair) for the camping types even if they don't allow it.
4. Folding cooler and backpack for beer and or ice cream runs at camp, this will make you very popular.
5. Ahh a supported tour, bring comfortable COTTON cloths and towels.
6. A big tent, why not someone else will be carrying it.
7. Use a single large duffel bag with backpack type straps for luggage, daily you have to move your bike and luggage at the same time, so you need your hands free for your bike.
That's all I can think of for now.