Can I have a standard form, specifically the pre-call questionnaire that can be different for different clients?

Yes, you can create specific forms and assign them to different people. For example the "Call Strategy" form, if you have different questions that need to be sent to different people, you would create a new form for each set of unique questions. Just create additional custom forms, customizing the questions, and assign the form to the person/specific people that need to receive the specific set of questions.

As an example, to create a custom Call Strategy Call:

Go to CONTENT > FORMS and click on the orange button button "ADD FORM" at the top of the page.

Type a name for the form (e.g. "Call Strategy 1"). After you save, a new section will appear for adding questions and assigning permissions for the form.