Are there extra consequences on top of maximum fine if I plead not guilty on my speeding ticket?

Could be. Why don't you slow down? Further, if you do stupid stuff in public, don't have illegal drugs or other bad stuff in your possession.

Check with the Court clerk but I suspect you can not go to traffic school unless the judge ruled you could. There is a fair chance the police officer will not show up, but it is entirely a gamble.

With your record don't look for any one to cut you slack. Get the best traffic court lawyer you can find and do what he says.

If you plead not guilty, your case will be set for trial. If the police officer doesn't show up for trial, the judge is likely to just continue the case to the next month's docket he will not dismiss your case. If you plead not guilty and you lose at trial, you will be convicted, but there will not be any extra consequences. If you want to take traffic school, you must plead guilty and pay the fine and then ask the judge to allow you to attend traffic school to remove the points from your driving record. Or, you can hire an attorney to get the ticket amended to a non-moving, no-point violation so it won't affect your driving record or insurance rates. It's also possible to hire an attorney to withdraw your guilty pleas for the previous tickets, and get those tickets amended to non-moving, no-point violations. It's even possible to do that with your marijuana possession ticket. You may not realize it, but that drug possession conviction will remain on your criminal record forever (If this happened in Missouri) and it can never be expunged from your record. Having drug conviction on your criminal record will prevent you from getting a job, renting an apartment, getting a bank loan, or getting a federal student loan.