On 1) it depends on per-question basis, I think. I would entirely omit long answer free-text answers. It should be click-and-go.
On 2) First of all you can show answers directly after choosing an option. That would directly create awareness (challenge —> reward). I would not add general questions (‘When was FB founded’). Have them all be topical, i.e. on privacy infringement, plus what they can do with you harvested data. Then if they have many question wrong, at the end, you can display a conclusion (“You are totally unaware of how surveillance capitalist works, and this is how you’ll be manipulated in the future…”). People with better scores get milder judgement ("You are on the right path. You protect yourself against the worst of FB practices. But you can do much better still, …), etc.
Then in the last page with the results also add a list of pointers to go further with the things that one has just learned. To sites offering alternatives and more protection, etc.