TurboTax does not provide any type of service where you can send written questions to a tax expert and have those questions answered, free of any fee. Nor would TurboTax have a service to assist you in completing three years of amended tax returns.
Your best option for your situation is to contact a local paid tax professional in your area to assist you with preparation of the amended returns and answer any type of questions you have concerning your tax returns.
TurboTax does have the TurboTax Live online editions where a CPA or other Tax Expert is available when preparing your current year tax return. That type of option is not available using the TurboTax desktop CD/Download editions.
Go to this website for the TurboTax online Live editions - https://turbotax.intuit.com/personal-taxes/online/live/