Male OE take longer to develop than the pullets. These have a ways to go before you can judge them for type and color. Also it is hard to judge a bird by pictures, especially ones pecking the ground. I see no major faults yet but Millie Fleur's never have the best of type and the color is always suspect. The pullets usually are the better in type and color.
Until the males have their full tail and hackles you will not be able to judge them. The biggest fault with Millie's( and all varieties that are considered "lesser") is the tails feathers are too narrow, wing carriage is low and hackles are not full.
Keep in mind that the older they get the more white they get, that is why you rarely see cock birds of good color.
As far as dubbing- the general rule is when the sickle feathers are finished out that is when you dub them. I wait till the weather is cool and do it at night. There are numerous articles out there including a book put out by the ABA. Dave Sherrill's book on OE also covers dubbing. It is also offered by the ABA and should be on their website.
I have NEVER heard of someone dubbing chicks.
For the record I raised and showed Millie's and Blue Millie's for 3 years. Only because my wife made me. They are interresting but just have too many issues for me. I have bigger fish to fry.
Bob