Bonus 2005 and taxing it 2006

[dodgersmum]

Arizona...
On December 6th I gave my employer a resignation letter. I had accepted antoher job at a larger company. She asked to take me to lunch Dec. 9th. She asked me to stay and told me that she would match what they offered me if I would agree to stay 3 months. When we got back tp the office she wrote me a check for 4k and told me that it was my Christmas bonus and back pay for the reveiew that she was supposed to give me in October. We made several verbal agreements upon me staying about how she treated me and such. The very next week she got verbally abusive and I decided to call the other company and go with them. I figured that I would not be out anything since the pay raise was what she used to keep me. (that and my loyalty!) I was due for a paycheck January 3rd for the payperiod Dec 19-30. On January 4th she told me that they would be withholding taxes from my bonus given on Dec 9, 2005. (I walked out 2 days shy to my 2 weeks notice being up) I knew that that would be a signifigant part of my check and I asked them not to do that and signed an Exempt Fed tax form. To this day I still have not received my check and she claims that I will not receive that pay or my unpaid PTO hours that I earned and did not use (accumulated per paycheck). She also claims that I violated an agreement to stay for 3 months which she is now claiming the bonus was for.
My questions are:
1. If the agreement is not in writting then is an employment agreement bound by law?
2. In result of this am I liable for a he said, she said repayment of my bonus?
3. If the PTO in the employee manual is listed as: "Upon termination of employment, you will be eligible to receive pay for all accrued but not used PTO", then am I not eligible to receive it?
4. What are the requirements for payment of that check an the final check for the few hours I worked and my PTO?
5. Finally is it worth fighting for?
Thanks, Completely frustrated!