I have got my passes for Discover Dog's stand, they are valid for entrance on all four day's for 2 adult's and 2 dog's do's that mean we can go and look round on all day's even if we are not manning the stand on those day's.

Yes

Do you know if Disabled Blue Badge holder's are required to pay the car park fee,

Hi

No the yellow or new blue badges dont have to pay the car parking fee
plus if you tell the gateman you have the badges there is a carpark a little
nearer.