Thanks for the questions! We'll answer them point by point.

1. Yes, that is correct. Characters won't know what their regains will be until they get them.

2. Per the FAQ, characters can regain the abilities they have listed on their application and ONLY those listed on the application. In Rapunzel's case, if you would like her hair to be a potential regain, she would have to be taken from a canonpoint where she has that power and it must be listed on her application. Hope that helps!