RE: Eating the bird!
Thats a good book for spaniels.
Get a good universal program, one that is not breed specific.
I like Evan Grahams Smartwork series, Mike Lardy's Total Retriever, Dahl's 10 minute retriever would suffice.
FF is a huge subject, not something that can be covered on this forum sufficiently. What you are doing right now is NOT FF... Not to say your doing something wrong, just dont want you to have the wrong assumption.
Stop where you are in training and explore some different materials. (Evan Graham is an excellent guy, and a top notch trainer, I really like his DVD's).
Collar conditioning is another huge subject.
Your askingPint sized questions that deserve 55 gallon drum sized answers.
Collar cond. is simply introducing the dog to the collar in such a way that the dog realizes that the pressure from the collar is a direct link to you the handler as a correction and not some random act of god... The dog understands that it cannot run from the pressure, the dog knows how to turn off the pressure by complying with commands asap.