Expert Help

I need to figure out a better approach to get expert help on my taxes.  I have been using TurboTax for many years and I am fairly experienced in how to use TurboTax, but I am certainly not a tax professional.  For that reason, I often review my taxes with an accountant before I file, but most of the accountants I know don't use TurboTax at all. I'm very interested in finding either an accountant who works with Turbo Tax or using the TurboTax Live expert help capability and I have some questions:

1. Is TurboTax Live expert help only available with TurboTax online? (not desktop)
2. Is there any way to upgrade from TurboTax desktop to TurboTax Live or do you have to start your return with TurboTax online?
3. I have both a business and personal tax return:
   1. S-Corp for Business
   2. Personal tax return that is not simple with some Schedule C book royalties
      Can I get expert help for both?
4. I've been using TurboTax desktop for years, but I have never used TurboTax online.  How do I use Turbo Tax online?

Thank you,