Most of the answers to your questions will depend on the practices at the center where you have the procedure done. The preparation isn't pleasant, unless laxatives & their effects are part of your kinks. I found that following instructions that call for a low residue diet the day before the prep begins makes everything easier. Not nearly as much "stuff" to clear.
There are many opinions on sedation. My choice has been to go without both times that I have had the procedure, and I will do it that way again. You don't feel the camera as it probes your intestines. If we had nerves that would let us feel all the movement of food through our digestive tracts, we would go insane. There is, however, something between discomfort and pain from the pressure generated by the gas they use to inflate the colon. In my experience, it was minor, no worse than moderate intestinal cramping. The other place you feel some discomfort and irritation is the "point of entry". After all, about 5 feet of tubing with a camera on the end is worked in and out of you, sometimes backing out, changing angles etc. to help it complete its journey.
If this freaks you out, get the sedation. If you are tense or anxious, you will tune in to the pain, and everything will be more difficult. The doctor will have a harder time threading the camera through you if you can't relax your abdominal muscles. Reactions to sedation vary widely, but most people I know do fine. The day won't be productive, but there aren't any truly difficult side effects again, for most people.
Privacy has been good in my experience. You will need a driver for the trip home. Usually, a friend can be with you until you are taken back for the procedure itself, and again as soon as the sedation begins to clear. When you are sedated, you are watched by a medical professional at all times. Almost always, the sedation is at the "twilight" level. You can still follow instructions and respond to the doctor, but there won't be a normal level of awareness, and very few if any memories. You aren't totally "out".
While this forum can provide you with a lot of opinions and people's experiences, these are decisions to be made with your doctor, who knows you, at least somewhat, and who can assess how you will most likely respond to both the procedure and the sedation. I do know that most people do opt to be sedated, and it is just assumed that you will. You will need to opt out if that is what you want..