You know what they say, your first reaction is usually right
Try not to change more than 10% of the answers that you flag for review. There are some questions that will jog your memory and you will legitimately revisit a flagged answer and know that your answer is wrong. Unless there's strong justification for changing an answer, don't do it. If you do change answer, keep it to a minimum.
ITTOs are a pain but the key is to understand them, not just memorize them.. You can also use mnemonics to remember some of them as I did and I'll be glad to share that spreadsheet with you if you'd like but it's based on PMBOK 4 so I don't think it's worth the potential of getting confused by.
I think you're on the right track and well equipped to pass the exam. Don't worry, go through more exams using the technique I mentioned (reviewing the answers after submitting a blank test rather than spending 4 hours on the questions) and it might be the fastest way for you to 1) gain confidence that you KNOW the right answer, and 2) make best use of your time to identify new concepts that you may not have encountered before (mostly terms).
Feel free to reach out to me if I can be of any assistance at all.
Yasir Mehmood, MBA, PMP, PMI-ACP, CSM, CSP, CLP (LeSS), CSPO
Community Moderator