As an EB-5 direct investor, how should I deal with my expiring E-2 visa while my I-485 is pending?

Advisable to do this.

You have a few options: 1) If your E-2 enterprise is operational and/or you are still working for the E-2 enterprise and your E-2 visa stamp is valid, you can travel abroad and reenter the U.S. in E-2 status before filing your I-485. CBP will likely provide you with an additional 2 years of E-2 status upon readmission. I would recommend waiting a minimum of 90 days prior to filing your I-485 after readmission in E-2 status. 2) File an E-2 extension application in the U.S. with USCIS before you file your I-485 application. This extension application could be challenged by USCIS due to the fact that you have an approved I-526 petition and the conflict between the non-immigrant intent required by the E-2 visa program. 3) Apply for a new E-2 visa abroad and reenter the U.S. in E-2 status prior to filing your I-485. You will have to disclose your I-526 petition on the DS-160 application. I would recommend waiting a minimum of 90 days prior to filing your I-485 after readmission in E-2 status. 4) File the I-485 and let your E-2 status lapse. You are allowed to remain in the U.S. during the period of time your I-485 is pending so long as you were in valid status when the I-485 application was filed. However, you will not be able to work for your E-2 company after your status expires (assuming you did not file an extension). You would have to wait until your EAD work permit arrives after filing the I-485, which could take numerous months.

You may be able to renew the E-2 now, but E-2 is not a true dual intent status like its cousins the L-1 and the H-1B. At some point, the EAD associated with the I-485 is what you need to continue working.

You do not have to, but you will be grounded in the U.S. without a visa in your passport. AP based on EB-5 takes 18+ months to process.

You must renew the E-2 preferably before you file the adjustment. If you engage in unauthorized employment, even after you file the adjustment, you can be denied, so it is critical you maintain continuous work authorization filing an E-2 extension of stay.

Generally, if you file your adjustment of status application prior to the expiration of your current visa status, you do not need to worry about renewing your underlying E-2 visa. However, due to current delays in adjudication of travel documents and employment authorization documents, you may need to consult with your attorney regarding the best strategy for you. You may want to file for extension of your E-2 status just to preserve your current ability to work for your investment enterprise.

If you have a pending I-485, you are not required to maintain the underlying non-immigrant status. You can continue to remain in the U.S. as long as the I-485 is pending. Whether or not you should still renew your E-2 is a different question. Your attorney should advise you on this issue based on the specific circumstances of your case. Good luck!