When do they get their true adult coat? I have a seven month old here who had a beautiful puppy coat and slowly the sides have become what I would consider "open". Is there a chance that his adult coat is still to come or is he what he is?

Seven months is nowhere near an adult coat. I would look more at his parents' adult coat than worry too much about his interim puppy coat.

I think that depends on the line. You may be seeing part of the adult coat now. I don't consider a 7 mo. old in puppy coat. You can hope for it to continue to develop in a proper manner.

It depends on the lines, the time of year and the weather...
I have had dogs blow puppy coats at 12 months and 6 months!!