You are confusing the legal standard for "dismiss" or dismissal with the issue of credibility of the witness. In order for a the court to "dismiss" a ticket, there must be no basis for jurisdiction, either subject matter or personal, over the action. Alternatively, the court, sua sponte (on its own) decides that there is no reason to continue the action in that court, such as attending a "defensive driving" school and agrees to dismiss the case in lieu of prosecution. The fact that the officer wrote down the wrong number, wrong letter or wrong expiration date of the tag does not constitute a legal basis for dismissal. It may, however, serve as a basis for cross-examination for his ability to recall specific fact.
This question comes up frequently on this board - is a ticket invalid because the officer made a clerical or a "scrivener" error on the citation? The answer by every lawyer in every jurisdiction that has replied is a simple 'No.' Clerical errors on a ticket do not equate to an automatic dismissal of the charge. [Further, the issue of whether the letter was an 'O' or a 'Q' is really a stretch - in my opinion, no judge would take your argument seriously.]
You are thinking defensively, which is good, but it is not enough to dismiss a ticket. The LEO still probably got the car's make, model, color, and Drivers License correct. It's too minor of a mistake to get a dismissal. It's usually best to hire a attorney who can appear on your behalf. Do not go to court and try and argue over one letter. I would not do it myself. Seat belt you will not be able to do anything about. Get the FL license plate or tags. For the stop sign, I don't know what you record is like. If you have a clean record, then you may just get a fine with no points "In your corner." Please click on the website. Thank you.