Yes, it can be done, and no, it is not heavy duty!
Here is my take on it:

Option Explicit

Const textFF As String = "First_Name"
Const checkFF As String = "Yes/No"

Sub FindText()

Dim rngFind As Range
Dim i As Long

i = 1
Set rngFind = ActiveDocument.Range
With rngFind.Find
   .Text = textFF
   Do While .Execute
       AddFormField textFF, rngFind, textFF & i, "Enter your name"
       i = i + 1
       rngFind.Start = rngFind.End
       rngFind.End = ActiveDocument.Range.End
   Loop
End With

i = 1
Set rngFind = ActiveDocument.Range
With rngFind.Find
   .Text = checkFF
   Do While .Execute
       AddFormField checkFF, rngFind, "Yes_No" & i
       i = i + 1
       rngFind.Start = rngFind.End
       rngFind.End = ActiveDocument.Range.End
   Loop
End With

End Sub

Sub AddFormField(strType As String, rngFF As Range, _
   strName As String, Optional strDefault As String)

Dim frmfldReplace As FormField

Select Case strType
   Case checkFF
       Set frmfldReplace = rngFF.FormFields.Add(rngFF, wdFieldFormCheckBox)
       With frmfldReplace
           .Name = strName
       End With
   Case textFF
       Set frmfldReplace = rngFF.FormFields.Add(rngFF, wdFieldFormTextInput)
       With frmfldReplace
           .Name = strName
           .TextInput.Default = strDefault
           .Result = .TextInput.Default
       End With
End Select

End Sub