This can be done. It will require someone with knowledge of programming. That programming can be traditional vba or the more arcane field codes.

• The easy way is with vba - a userform. A userform is a custom dialog box to gather information and act on it. If done using vba, the user has to allow macros to run. The developer has no control over that.
• The hard way is with fields and IF Fields to test responses and conditionally include text. If done this way, unless the fields are unlinked, all of the information will actually be present in the Word document. If you save as pdf after the choices are made, that would not be the case. After the choices are made, the user would need to update the fields in the document. Also, the IF fields would need to be updated. If done using fields, I would use Mapped DropDown Content Controls rather than checkboxes even for Yes/No answers.
  Field codes can be much more difficult to debug, for me, at least.

Resources:

• Create a Simple Userform by Graham Mayor, MVP
• Create & Employ a Userform by Greg Maxey, MVP
• Create a Form Using Word Content Controls by Greg Maxey, MVP
• Repeating Data Using Document Properties Content Controls and Other Mapped Content Controls

This is not something you are going to get done in an afternoon. For me it would likely be about a 50-hour project. Others who regularly post here could get it done more quickly I suspect, but it still would not be in an afternoon.