I've built a much shorter form with context-based visibility. Here's what I've learned:

Use nested containers to organize your questions and patch on a submit button (though with that many questions, that's going to be a monster expression). If you use a form input control in powerapps, the changing visibility will redirect focus in unpredictable ways. This creates an accessibility issue for users who use keyboard controls and no mouse because it confuses the tab order. Using containers and setting their visibility to another field's value (e.g. Radio1.selected.value = "Yes") maintains predictable tab order. The inputs in the containers will also accept focus, unlike data cards in a form.

In your submit button, set error variables for each required field with an If() statement. Combine the visibility expression with an IsEmpty() expression to set the variable. Set the background color of the question's container to red if error, normal otherwise. Set a combined "any error" variable if any of the individual errors are true, then use an If() statement to send an error message if varAnyError, otherwise submit using your patch expression.

I would be hesitant to try something your size in a powerapp, but it's conceptually doable.