All your buttons are technically submit buttons.
Add a field to your form i.e. FormStatus.
Your 'save' buttons submit the form to the library. Allow the form to over write itself if it is an existing form. Don't change the form status or change it to 1.Draft.
You can then have your form open to whichever view you like with a form load rule and the form status field condition.
On your 'main/Final' submit button, change the set a rule to change the FormStatus to 2. Complete.
Your workflow can run when the form status = 2.Complete.