Check out childcare choices it should tell you what your entitled too. https://www.childcarechoices.gov.uk/
Yes you should be, I work 23hrs and my OH works full time. We were entitled to the 15hrs since September, which will go up to 30hrs in next September
As long as you do atleast 16 hours at minimum wage you should be fine.
You should be. Go on the www.Gov.uk website