Do I need to include my T5008 if my values are zero?

You do not need to complete a T5008 form as well if you have already made your entries in the Capital Gains Profile. You should remove your T5008 slip entries as they are not complete and reporting the loss you incurred.

You can choose to enter these slips either way, on the T5008 slip page or in the Investment section. The Capital Gains or Losses from either entry methods will transfer to Schedule 3 of the tax return.
 

If you enter your T5008 slips (or use the CRA AutoFill feature to import) on the T-Slips page in TurboTax, do not enter them again under your Capital Gains & Capital Gains Deduction Profile, and vice-versa. Doing so will cause double reporting.

Thank you for choosing TurboTax.