You can enable/disable template options by opening a template, clicking Template settings on the main page, and then selecting the Other options tab.

Options available to customize:

• Allow participants to invite others to help: On by default. If you disable this, the owner participant will not be able to invite other participants to plans. Users will still be able to invite participants.
• Enable comments: On by default. You can disable commenting on plans by disabling this option.

When you're done, remember Save changes.