Carrie, I'm happy to give you some opinion here, but recognize that this is MY opinion ... and it is not the opinion of your medical director. That is the only opinion that stands in your clinic. So, here we go. And, pardon me, but all of the scenarios that you pose are examples of medical decision making. Most of the 'answers' would be, "it depends."
1) If a patient in my clinic had an ox-tox seizure, it would depend on the trigger for that event. What were the contributing factors? Too much narcotic with CO2 retention and the resulting vasodilation in the brain? Was the patient febrile, vasodilated, and subject to this event? Are you completely sure that the seizure-like movements weren't really an event with hypoglycemia? These events can appear to be identical in manifestation, but they are not identical at all.
Given that your scenario is a simple seizure and you think ox-tox, I'm not sure what you mean by "no lasting effects." If the patient recovers quickly (5 - 10 minutes) and has a normal neurologic exam, then the first decision is to terminate the current treatment ... treatment for what indication for HBOT? There is a huge difference between a diabetic foot ulcer patient vs. decompression illness and spinal cord damage. The DFU, I would cancel today's treatment and start again tomorrow. The DCI case, I would give a 15 - 20 minute 'air break' then start again. I might shorten the O2 breathing periods by 5 minutes (from 30 minutes to 25 minute segments) then carefully observe the patient during the rest of the treatment, but I really don't think I would terminate this treatment ... but, all is conjecture because every patient is different.
2) I've never seen a patient with difficulty clearing ears but had a 'normal' ear exam after the treatment or prior to the next treatment. There is 100% damage to the tympanic membrane, and you need a thorough examination of the drum after the treatment. The damage may be clinically minor but frequently results in a TEED 2 or 3 trauma. The alternative therapies that you list are entirely good, but totally determined by physical examination. Every case is different, and I've done each one of them at some point. Again, your medical director is the one that needs to take charge of this and make clinical decisions.
3) I disagree with your conclusions about pneumothorax and/or pulmonary edema. If a patient needs to be treated (HBOT for severe trauma), then patients come to HBOT with chest tubes. These need to be converted to a Heimlich valve but certainly can be treated in the chamber. I've done it many times.
If the pulmonary edema has been cleared and whatever event caused it has been evaluated, then I may/may not treat the patient in the future. The key to all of these scenarios is not what compication occurred, but it is WHY did the event occur in the first place. If I can determine the root cause, then I can make good clinical decisions as to treat/not treat questions.
So, in summary, resuming treatment on each patient has a simple answer, "It depends." I hope this is helpful, but I don't think this is the answer that you were hoping for.