He should go see the probation officer on Monday and sort this out. It is always easier to ask for permission rather than forgiveness. There is clearly a disconnect between the probation officer and the supervisor.
As trial apporachs it is common for the lawyers to meet. They may be going over evidence. Moreover the severance motion is still on the table. i suggest you march yourself down to your lawyer's office and sit and wait for him and see about the status of yor case.
A lawyer can REALLY help you out here. There are diversion programs which will allow you to expunge your record. BUT you have to be signed up for the right kind. your friend's advice is dead wrong. Do not take advice from a lay person. Hiring a lawyer will be the best money you spent.
Almost certainly. You could be held for weeks in Texas ( not a happy event) pending extradition. Make your way back to California and address this with your probation officer. It is easier to ask for permission than forgiveness.
I suggest you fight this one. If the "light" was a camera it would be easy enough to photograph this and bring it to court to show the judge. This is certainly a case were contesting the ticket is a valid exercise of your right.