Really any dog can have epilipsy. We had a mutt and he had it very bad...at that time meds were not around for dogs and the poor little beggar suffered.
The shedding is really not a problem for me either. I have another mutt and she sheds like you wouldn't beleive!!! Get a rubber tooth comb for the short hair breeds as it doesn't hurt nor scare them.
I agree that it is nice to know the breeder and know what basically your pup will be like. But don't be discouraged from a rescued Dal too as most of them want to be loved and would appreciate a great owner. My therory: You take your chances with anything.
You were asking about the tracking. Lizzy my Dal constantly has her nose down and sniffing what ever. She tracks her toys down...I imagine that it would be easy to train for scent???? My borderx dal is one of the greatest retrievers ever. People marvel at how she goes and when she comes back she will throw whatever at you. She loves to retrive. I think its all in the way you train. Get the dog used to the duck dummy.....or if you are hunting now keep some of the feathers for scent..and make a duck dummy. Put it in a bag (plastic) till you are realy to use it.