Ditto at big brown - I think with us any money left over in the ticket bank after 3 bid periods (which equals 6 months) goes back to the company. It might be 2 bid periods (4 months), can’t remember.
Some foreign airlines will allow you to credit your miles to their alliance partner. For example when I flew on Singapore Airlines I added my miles to United’s Mileage Plus program. You can do that with Lufthansa, etc. too – all Star Alliance partners.

We get miles on pretty much any airline we commercial on (it’s up to you to furnish a frequent miles account number to scheduling which they store in your profile). Lately Delta has been "taking away” miles for some guys. Happens only now and then but I'm now avoiding Delta and fly on other airlines.