Yea, there is absolutely no way in hell I would use any pressure treated wood INSIDE the house. That's just a bad idea and a 'pro' to say otherwise may understand construction, but not chemistry or biology. Off gassing, whether it be from wood, carpet or anything else is a REAL issue and people suffer (and even die) from it all the time. I am NOT a contractor but metal (my whole house is metal stud, but no basement) will probably have issues with moisture as well. I would probably be looking at engineered wood, like the synthetic deck material. Depending on the plastics, etc. it may have slight off gassing as well, but nowhere near as bad as pressure treated lumber.