If she does not pick one friend, they will think she dislikes them. Any friend she does pick, depending on who it is, their reaction will be different. From smug, to awkward, to embarrassed, to “oh, um, sorry, but um, I don’t think of you that way,” to hopeful. Applejack just wants it to be her.
Yes.
Or with Applejack, who could probably farm that land so that food wouldn’t be a problem.
Maybe she knows that Twi would feel like she’d need to answer the question regardless.
You would think Pinkie would know the rules of Truth and Dare.
She chose Applejack and Fluttershy.
One of those was a good choice.