> From what I gather, blue shouldnt produce any health risks - I have looked into it, so please let me know if I am wrong.
It shouldn't according to many things I have read, however, it has been known that some blue's suffer more with skin problems, etc. However, it could also be said that the Stafford in general, can be prone to skin problems anyway.
I have also read that the pigment cells are directly produced along with the same cells that give rise to the nervous system. It could be assumed that if you have defects in genes associated with color genetics you might also have nervous system defects because both types of cells are derived from the neuronal crest.
(AKA colour dilution alopecia).
As Nova has mentioned re: the blue colour in the showring, lack of good pigmentation would be one of the prime reasons why the blue's sometimes don't do well in the showring. However, there are a handful with very good pigmentation which are being placed at shows.
>I have read loads of times that a premium should not be paid for a blue SBT as they are not rare or difficult to produce, but I havent yet seen any evidence of this unfortunately
Just do a search on the internet for blue Stafford pups, and then you'll see why they're not rare or difficult to produce! The advertisements are 10 a penny!
As Brainless has already mentioned too, a KC registration does not necessarily a good breeder make.