F1 + OPT how to file tax?

I was an F1 student from 1/05 to 6/28/05, and on OPT from 6/29/05 to present. Did not file for H1 application until 2/06. 2005 is already beyond the 5th year since first entry to US as a student.

F1 income includes both fellowship and research assistantship. OPT income has been deducted social security and medicare taxes.

Should I use 1040 NR or 1040 R? How about 8843? I used NR-EZ for my 6th year after I called IRS and was told okay since I was still a student. How about now that I am into OPT?

Does $5000 treaty deduction still apply? Is fellowship still exempt?

May I get back the social security and medicare taxes?

How can I claim for moving expenses?

Thanks.