I have done several ACA tours, including the "self-contained" variety. RE the self contained trips, here are my thoughts on your questions:
1. There is no support vehicle. You carry everything on your bike. As to food, most often the designated cooks for the day are purchasing food at the end of the day at a market/convenience store/whatever relatively near the designated camping area. They are purchasing food to make dinner for that evening, for the next morning's breakfast, and lunch the next day. All riders carry their lunch on the bike....although nothing stops you from stopping on your own for a "second breakfast" or lunch at a place along the road.
On occasion, the group will "live it up" and have dinner at a restaurant. Frequency depends on the itinerary and budget.
You will need to leave space on your bike to carry some "group" gear such as camp stoves, cooking utensils, pots, and usually left over group durable breakfast/lunch food items.
2. Pack weight is highly variable re the individual obviously.
3. ACA will give you guidance re what kind of lock to bring. Typically they recommend light weight cable lock of some sort as opposed to heavy u lock/chain. I have progressively carried lighter and lighter cables...most recently super light weight cable that I use to lock downhill skis. Be aware of surroundings/where you leave bike, etc. My approach would likely change if a tour will bring me through more urban areas on regular basis.
4. During a riding day, you are free to ride at your own pace and pretty much do your thing. There are no designated "rest stops" Some folks might be speed-oriented and want to get from A-B fast and chill at campsite. Others stop constantly to go swimming in lakes/rivers or whatever. Some sightsee. Some stop for ice cream. It's not some overly orchestrated thing. Chill and enjoy.
Note the leader usually rides "sweep" in case someone runs into mechanicals or other issues. That can vary.
5. Don't recall wake up time....there is no specific "bed time" LOL. If you are on cooking duty, you will have to get up earlier in the AM to make breakfast. No biggie, breakfast is simple. But otherwise, break camp at a reasonable time. Also, depending on trip/itinerary, you will have at least a couple/few "off days" where you can enjoy the surroundings, stay off the bike if you want to. You can lounge and sleep in if you want on those days.
6. Showering schedule is highly personal. I typically do it sometime after arriving in camp in late afternoon/evening. Plenty of time to get things done in evening and mornings, frankly. Unless you are a sloth.
7. Camp site arrival time is generally up to you and, of course, dependent on the mileage/difficulty of the riding day. Highly variable. And, like I said, depends on your approach and goals for the day. So, if I am on cooking duty, I am motivated to ride faster and get in to camp earlier so I have time to set up, shower and go shopping. On another day, I might enjoy a second breakfast, go swimming and generally take my time. On another day, maybe just hang out riding with someone in the group.
8. Average speed...up to you and I usually don't pay attention to it on tour.
9. Read the various info that ACA sends out with the tour info after you sign up. Plenty of good stuff in there...handbook and specific itinerary. You will also be made part of online group/email list and you can always pose questions to others in group or tour leader(s) prior to the trip.
Enjoy.
