I used to jump/skydive in my younger days. To answer your first question, if you can fly on commercial aircraft you should have no issues with any pressure changes during the dive. The situation you should be prepared for is a rough landing (worst case scenario). If you cannot suffer a sharp blow to the head -- you will be wearing a helmet -- then you should not risk the jump. This you should discuss with your Eye MD.
Glenn
Your question should be directed to your Eye MD retina physician. Only he/she can answer either/both of those two questions.
JCH III MD