You will probably have better luck on the Backyard brahmas thread....they tend to converse more than we do on this one.
Pyle is a misnomer....you probably have what we would call splash here in the states. Splash comes from breeding blue to blue, pyle is dominant white on a wildtype partridge...it doesn't sound like that is what is in your line as you describe it. I'm sure I'm not describing it correctly, but the just is that if you breed one of your splash to a wildtype partridge (not blue) you won't get splash, you'll get blue. If you breed a pyle to a wildtype partridge some of the chicks will still be pyle. Just something that you should know since we tend to get confused when someone says that they have pyle.
As far as your questions go, yes there are varying degrees of foot featheredness (what a word!). Yes, they can have too much, or too little. The standard simply says "well feathered". My take is that they should have feathering on the outside half of the middle toe and all toes out from there. I think it is probably too early to tell on your chicks how their foot feathering will turn out, at least I've never been able to tell in chicks.
I feed high quality feed. I don't think it matters whether it is vegetarian or not...it is hard to find any that isn't vegetarian these days. I don't feed my chicks eggs and I keep them on chick starter until I put them in with the rest of the flock, usually around 6-8 weeks (depends on when the next hatch needs space in the brooder). At that point, they go on grower feed....that is what I feed all of my birds with 20% protein. I keep oyster shell free choice for the laying pens.
Telling blue from gold isn't very easy in young birds. Usually I can tell when they are about 6-8 weeks old, but not always. I've never been able to tell the colors from their chick feathers....right now I have a brooder full of darks and splits and I have so many different degrees of color from blonde to almost black.
Hope this helps, join the backyard brahmas thread....they are more active over there than we are here. We tend to get too technical and serious over here for most folks. :/