You are welcome.
1. That is not recommended. You can switch products here: How do I switch from TurboTax Online to TurboTax Desktop?
2. No, because TurboTax doesn't support e-filing of a return with a 3115.
3. No, it is not an addition to rental income. It is a decrease in expense, which essentially gets you to the same place for net income. When you have an unfavorable difference, you can spread the addback over 4 years instead of 1 (481(a)).
