The concierge floor is the top floor--I can't recall exactly which, either 5 or 6 if I recall.
They do have dedicated non-smoking rooms. They also have both garden and boardwalk views.
We really enjoyed the BWI.
That said, the BWI is probably the least child friendly of all WDW resort concierges. Of course your children will be welcomed, but the lounge isn't particularly child friendly, the norm seems to be that there will be more adults than children there, including busines travelers. I don't recall seeing any toys in the lounge, no smaller tables and chairs, and you're more likely to find the tv tuned to CNN or ESPN than the Disney Channel.
Like I said, your children will be welcomed, but you might feel more comfortable at a different resort. The Beach Club, AKL, and Polynesian resorts are all VERY child friendly.
I know if I were going with my young niece or nephew, I would not choose the BWI concierge.
Just some food for thought.
Anne