There is no difference when it comes to punishment. Both carry a maximum of 20 years in prison. The theory of proving what the defendant did is a little different. Being charged with Armed Robbery means the State must prove that individual was the principal person who committed the crime. As for party to a crime, the State must prove they were merely involved with the planning, encouragement, etc. Party to a crime is like the get away driver.
If the medical personnel at the hospital deviated from the standard of care they could be held liable. I would suggest you contact an attorney that practices medical malpractice and discuss the case further. I would do this sooner than later.
I would speak with an attorney in your area to see if they could reduce the charge or get it dismissed for you. If you cannot afford one, speak with the prosecutor on your court date and explain your side of it. If they do not agree to reduce or dismiss the ticket, then you can have a trial on the issue.
I would go there in person and ask to see your probation officer. If you called the probation office with your cell phone, keep the records, you can go online with your provider to get a copy instantly. Also, get a note from your doctor or proof you went to the doctor at the time of your appointment. There is no telling what the probation officer will do, so be prepared.
If you are charged with a felony charge like Arson, I would recommend hiring an attorney. He/she can speak with the DA about the evidence they have against you. They may be able to continue to prosecute you with other evidence they may have.
It depends on the Court you are on probation with and the Judge. Also, if you have any prior probation revocation. I see you are from Kennesaw, if it is one of the Municipal Courts, like Acworth or Kennesaw, probably a little to no jail time. If it is in Cobb County then it will take some negotiations with Sentence Enforcement. Also, you will need to deal with the new case. You could face possible jail time and more suspension time.
I am curious how you left Arizona without going into custody or having a report in date. Georgia jails will not house you on a sentence from another state. You can always file a motion to withdraw your guilty plea if it is available in Arizona. I would follow the advice of your Arizona attorney.
If you are arrested and fingerprinted, you have an arrest record and it will show up on GCIC. You can check for yourself, by going to any law enforcement office and pay to have your criminal history ran.