What are the risks of having multiple cosmetic surgeries at the same time?

The sequence of operations you anticipate does not sound like it will induce any significant operative risk. Clearly, the overall risks to the patient will be assessed by your surgeon in your anesthesiologist

Combining procedures is very common, however it will depend on your health. See a Board Certified Plastic Surgeon to help you determine how safe it is for you to have multiple procedures. Good luck.

There are several things to consider. More procedures means more time on the OR table and a longer time under anesthesia. The longer that you have anesthesia, the longer it takes to wear off, and the less likely you are to just pop up feeling great. This is especially true if you are going to be under general anesthesia instead of a deep sedation. There will be a slightly higher risk for nausea and vomiting with more anesthesia. The next consideration would be for DVT and PE risks. There are some confusing but notable studies that have been reported about the risk of blood clots with combination surgeries, especially those that involve liposuction and tummy tuck surgeries. Also, the more surgical areas treated, the more difficult the recovery in terms of pain and soreness. With all that said, the procedures that you have listed are routinely done at the same time and can be done together very safely if you have a careful surgeon and anesthesia team.

and much of it depends on your health.  But the procedures you describe are done commonly and safely.  Your surgeon should be able to assess your health history and determine if your risks are minimal or not.

You have a medical history which we do not to help assess risk.  The Caprini risk model help determine risk of thrombosis.Please find an experienced Board Certified Plastic Surgeon
and member of the Aesthetic Society using the Smart Beauty Guide.These Plastic Surgeons can guide you on all
aspects of facial surgery, breast augmentation and body procedures including
tummy tucks or mommy makeovers!

Having these procedures done at the same setting is common.  Discuss your post op course with your Plastic Surgeon prior to surgery so you have a clear understanding.

it is up to your surgeon to go over specific riskes with you, but the combination of procedures you mentiion is common and does not raise your overall risk.

The biggest risk of doing too many cosmetic procedures in one day is that the lengthy time on the OR table increases the risk of blood clots in the veins which can dislodge and travel to the lungs (pulmonary embolism) and cause death. So, even if it sounds more "convenient" to do it all in one day, sometimes that's not the wise choice.