I'm planning to lay 3/4" solid hardwood (hickory or maple) from LL. I was going to use polyurethane glue I went to LL and the guy told me I shouldn't use glue, that it will void warranty on these products, because the instructions call for nailing installation. So to all you knowledgeable good people here, 2 questions: 1. Is it true that solid hardwood should not be installed on glue if the instructions don't mention glue and only mention nailed installation? 2. Is it true that AdvanTech OSB (an extra layer on top of subfloor) is bad, doesn't hold nails well, doesn't bond to glue, and so plywood is the only underlayment I should use? 3. Should I think about putting cork under that wood, or is 1/2" plywood(+ perhaps water barrier?) underlayment + 3/4" solid hardwood enough to absorb the sound? There's some contradictory information (or rather opinions) about all this out there, it's kinda hard to find anything definitive... Thanks!

I am using Armstrong T molding to transition between two laminates at a doorway. It has a metal track that attaches to the floor and the T molding snaps into the track. I used this upstairs, but I could screw the track to the subfloor. The now project is on concrete. Do I just use adhesive like Liquid nails to attach the track to the concrete? If not, how do you attach it?