Will I pay Philadelphia/PA city and state income taxes? Yes, income taxes on the income you earn once you become a resident.
Will I have to pay any NYC/NY city and state income taxes because I will continue to own my apartment there, but will not be living there? Yes, income taxes on the income you earn once you give up your residency and the rent earned on the NYC rental. You need to give up the homestead on the NY residence once you convert it to a rental so you can avoid NY income taxes on the PA income.
How will my move from NYC to Philadelphia for a job impact my taxes? In the year of move you will file part year PA & NY returns ... after the year of the move you will file resident PA return and a non resident NY return ( compute the NY return first so you get credit on the PA return).
Will I end up paying more in taxes? Not really ... see the prior answer for the correct way to file.
What is the best way to file my taxes so I paying the least amount of taxes? The best way is the correct way ... in the year of the move you may want to use a local tax pro to get this done correctly, set up the rental properly and get educated on what can be a complicated situation with the PA & NY state taxes & the local/city taxes.
