It is the normal tissue reaction to the injury (surgery). It will slowly progress during the first few days. It normally reaches its peak at 72 hours after the surgery and slowly improves after that. I suggest to keep the area elevated, and use cold pack during the first week after the surgery to minimize the amount of swelling. The swelling will improve in the second week and continue to do so during the first month after the surgery. However, the eyelid and the lip will swell more extensive and last longer than other body parts.
It is the bleeding in the tissue. Its seveirty depends on the amount of blood that leaks from the vessels after the wound is repaired. The bruises will be more noticeable in 3-4 days after the surgery, not the first day. Some people seem to bruise much easier than others. In order to minimize the amount of bruises, I recommend all of my patients to stop all NSAIDs (aspirin, ibuprofen and the likes), all food supplements and all unnecessary drugs at least 2 weeks before the surgery. Once the bruises appear, it will significantly improve after 2 weeks and completely resolve by a month.
You can resume normal activity the day after surgery. For tummy tuck, you need to make sure you get out of bed the next day after the surgery to minimize the chance of adverse events. You can start light exercise at 2 weeks after the surgery and go back to normal routine exercise at 1 month after the surgery.
If you need to fly back home, I suggest you to rest in Thailand at least 5-7 days after the surgery before doing so. Also make sure to get the "fit to fly" medical certificate to prevent any problem at the airport by the airline staff.
I normally remove the stitches at 5-7 days after the surgery. If you need to leave Thailand before stitches removal, you can have the local surgeon to remove them for you. I use the self-dissolving stitches in the scalp and the mucosa, so they do not need to be removed.