This is going to be a very challenging app to create. With at least 3 fields per question, you're looking at 300 fields in the list. So first, I'd go double check to confirm that a single list will support this.
Also, having that many fields in a single form makes powerapps extremely challenging to work with. PowerApps was designed to create mobile apps, which typically have a few fields per screen. Yes, it can handle more than that, but that fact that it wasn't designed to do so makes it painful. For example, moving a bunch of fields around on a large form is slow and tedious. Even simply finding a field on a large form is difficult.
I'd recommend breaking the form into sections, and configure a separate SP list and PowerApps screen for each section. This will make reporting more challenging, but with 5 sections, that would be ~60 fields per list, which is far more managable than a list with 300.