With no air or gas in the eye no problem with flying, same with "thin" retina. The droopy eyelid is called "ptosis" and is a not uncommon post op complication of RD surgery
Most surgeons would wait about 4 months post op to see if the droopy lid improves, if not referral to an Eye MD oculoplastic surgeon would be in order to discss surgical lifting of the lid.
Thank you very much. I appreciate your reply.
Good luck.You can also find oculoplastic surgeons in your area at www.geteyesmart.org