1. If this S Corp had revoked his S corp election in NY, then he would have only be responsible to file NJ S Corp Tax?=======>>Correct; however, if the S corp terminates its tax status in the middle of its tax year, it might have to file its return. It will have to file a return covering the months during which the corp was still an S-corp. All income and losses from those months are reported on its return and the shareholders must include that financial data on their personal returns.
2. Since his S Corp was originally formed in NY but now he moved to NJ where he conduct all his business, would the business still be considered a resident in NY or a non-resident?=====>UNLESS THE S CORP IN nys IS TERNINATED, since the S corp is legally created by filing a Certificate of Incorporation with the New York Secretary of State, THE s corp is still considered a resident of NYS.
3. If it's consider a resident S Corp, does he still have to file a personal tax return for NY when he is living in NJ?====>As said previously yes Unless the S corp in NYS is fully terminated;an S corp is considered an independent legal entity under NYS law. S corp status is an IRS tax classification. Once of the consequences of corporate independence is that if you want to dissolve the S CORP, you can't just lock the doors and walk away. Before NYS will consider your corp legally dissolved, you must satisfy state authorities that certain formalities have been completed. You must also notify the IRS