Hiding content is a good solution if you want to have flexibility to revisit selections but not so good if the documents are going out to clients in Word format as you have no control over their Word options.

Looking back over your workflow, I'm thinking I would do this with a summary page at the top of the document and use linked content controls to allow your sales staff to enter the customer-specific info in a single location and then run a macro to remove the unwanted sections and blow away the summary page to leave you with a complete doc customised to that customer.

Summary Info
Customer Name: Click or tap here to enter text.
Business Name: Click or tap here to enter text.
Date of Meeting: Click or tap to enter a date.
Sections Required
☒ Introduction
☒ Section 1
☒ Data Subset 1
☒ Data Subset 2
☒ Data Subset 3
☐ Section 2
☐ Data Subset 1
☐ Data Subset 2

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Andrew Lockton
Chrysalis Design, Melbourne Australia