As far as smoking is concerned Terminals 3 2A-D&F had smoking facilities as recently as last year. Terminal 1 (which I believe is the new terminal) is completely smoke free.
Take a look at this site which has the smoking areas highlighted.
http://bonjourlafrance.net/air-franc...dg-airport.htm

Interestingly enough the official CDG website says smoking is banned throughout the complex. Just another prime example of French contridictions.

http://www.aeroportsdeparis.fr/ADP/e...t_airports.htm

If you are transiting you will need to reclear security. The doors leading outside are literaly 50 feet from the security checkpoint. You shouldn't have a problem at all.