This has nothing to do with my little chickens, but does the cha gene have an effect on the golden yellow leakage in lavenders? Since true black or bronze has gold leakage, wouldn't lavender on bronze have that yellow leakage (besides what is caused by sunlight and corn)
Yes it would. Lavender does not mess around with the Pattern, but it dilutes both Color Types. So a Bronze Isabel would be Self Blue (mostly) with the the Gold areas diluted to the cream shade of Isabels. I don't think anyone has ever bred this color, and I'm not sure what Lavender would do with the Bronze tones in the cocks' Saddles.
Yes he would. Leakage in blacks usually occurs in crosses and is only stabilized in two landraces. It can occur either when you have E/E; cha/cha; Co;co, or simply E/E, or E/e+.