Ginger is reported to be good for avoiding seasickness, although I'm not sure if your ginger candies have enough ginger to be effective.
High protein snack bars are excellent surface interval food.
Baby shampoo works as well as any defog liquid.
Ear drops, lubricating eye drops and skin moisturizer are all valuable.
Converse allstar sneakers work well as dive boots with some fins. They have drain holes, are good for walking across shore or parking lot, and get some street cred.
Tights for men and women prevent abrasion and stings when diving in warm water with only a rash guard.
Shopping plastic bags work for me in helping to slide into a wet suit.
Fisherman's neck gaiter helps protect from the sun. You can pull it up, put on sun glasses and a hat and be well covered. When time to dive you can leave it on your neck, or pull it up over the back of your head and secure with the mask strap.
A hood is a good addition to conserve heat.
Bring extra batteries or if yours are rechargeable, bring a power strip. Electric outlet adaptors if travelling abroad. Extra SD card for your camera
Inexpensive, small dry bag to hold room/car keys, snack, sun glasses, sunblock, dry shirt
Your report on weighting is interesting. Sounds like 8#s with only a rash guard might be too much?
Lastly, and most importantly, dive with an OCD buddy. They will bring all the tools, o-rings, extra batteries, de-fog etc. so you can just relax and take pictures.