#1 A female artist not from the US and the clue hinted to a certain mod's old username; now I practically spelled it out for you
#4 Former Disney star
#11 They also very recently released the lead of a soundtrack for an upcoming movie
#10 The vocals belong to a kid, hasn't charted in the hot 100 in the US, but in the UK it peaked at 4
#12 British Rock Band, really hard tbh, Marn probably can tell you more about it
#14 see clue #8