Hi Dr. Amit.,
Non deduction of PF is just an indication and not a conclusive thing to decide whether you are getting salary or consultation fee.
I would say, confirm this thing from your Hospital only that whether they are treating you as an employee or a consultant.
Now ur other questions -
1) In case of a consultant, the receipts/income will be treated as Professional receipts.
2) Service tax is not applicable to Doctors in general, even if u r being treated as consultant.
3) Car's EMI -
If salary - then no deduction will be allowed in respect of car's EMI
if consultant - then interest will be allowed as deduction & depreciation @ 15%shall be claimed (due consideration should be given to dis allowance on account of personal use)