Is there is a better chance to get a positive than a negative answer?

No, chances are balanced and completely random.

Can I get a new answer without closing and reopening the app?

iPhone and iPad: Shake your device to get a new random response.
Apple Watch: Press firmly on the Display and tap “Again”.

How many possible answers are there?

20 positive and 20 negative responses.

What is that font Deciding use?

It's called Miso.

I have a different question.

Write an email to deciding@superpixel.ch.