I'm presuming that you're talking about creating a table where each record represents an answer to a question, like an EAV model. Correct me if I misunderstand. One possible solution would be to design the questionnaire so that there's only ever one question in view at a time (form view), then switch to different layouts for each question, where each different layout displays the input field using a different control style (free text entry, pop-up, drop-down, radio buttons, checkboxes, etc.). This approach would translate well to IWP.
You are right, I imagine a table where each row represents a question and a type of answer. Your proposal sounds like a path to explore. I read in some discussions about conditional formatting and that it should be possible to hide or show objects. But I could not find such alternatives anywhere. Do anyone know anything about that.
In FileMaker Pro and FileMaker Go, conditional formatting can be used to hide objects, either by making them transparent (backgrounds only) or styling them to blend-in with the background. For the idea of layering different field objects on top of each other to reveal different input styles, you'd also want to layer an invisble button on top of the stack or an OnObjectEnter script trigger for each field that takes the user to the correct field object for the appropriate entry style for that record — it's kind of a pain to maintain, but I suppose separate layouts for each entry style could be a pit of a pain, too. Conditional formatting does not work in IWP.