During tempo it is okay to be breathing hard. That means your heart rate is def up. Just make sure you are not accumulating lactic acid in your legs and that you are able to finish at the same pace you started at . If not then you are going to fast. 65-75% id a rule of thumb however your better off on the slower side of thngs rather than the faster.
For the hills ….full recovery.. id say around 4 minutes