Dipsy,
you're assuming that a barred cock will carry two copies of the barring gene, and he may, but he also may not. If not then only half his progeny will receive a copy. Other than that, I agree with you.
Splash papa, black barred mama = blue barred sons and blue non-barred daughters. Approximately half of each will be frizzled (assuming that the frizzle is the usual heterozygous (one copy of the gene)).
Sebrightmom,
Anythiing other than white to white is unpredictable as a general rule. With specific birds and crosses you can make predictions based upon previous results from that particular bird or pair of birds.
Onthespot,
Good question. I have a somewhat similar looking bird (but add some red!): some definitely splashing, but it appears to be widely barred in places rather than unpatterned random splashing. Do you have a photo of your bird?
Any colour can "hide" other colours, either because the nature of the particular colour doesn't show on the plumage (ex. a laced black bird) or because it is recessive (ex. lavender or white).
I believe that the random nature of splash can hide some patterns that would be apparent on a solid coloured bird. But I think it depends on the specific patterns and colours involved. There are pattterns that include splash genetics.