Mick, as per (2) the trail (I call it the Lower Nine Mile Run Trail) itself is in pretty good shape, but I will admit most will be searching for a minute or two (from either end) to be sure they've found it. Keep in mind that there is still ongoing construction as I have seen heavy equipment working on the Old Browns Hill Road end of it, but you should still be able to use it. So from the Duck Hollow end, look for the construction equipment, on the Frick End look for something that resembles an old service road (two dirt tracks).
Also, if you want some real bushwacking, try your hand at that Sylvan Ave ROW path between Hazelwood and Greenfield. I almost got stuck and ready to pass out from the heat and dehydration last week (I had no cutting tool nor water). I still think that could be a great trail, it's just that right now it looks like a Vietnamese jungle.