So I didn't buy Cruel Youth's songs on iTunes i just downloaded them from apple music

does this help them?
or is it best that I buy the songs..

does it help them chart with apple music?

I think it counts as streaming so therefor would help the chart position?

Everytime you listen to it, it'll count as a stream. However, a sale would be equal to 1500 listens so if you don't plan on doing that in one week, buy it and let your streams pile unto that

You should stream her Verbalicious stuff so that she realizes ditching that was a mistake and goes back to it.