1. Its the force generated by the engine, measured in pounds of force, rather than pounds of weight. It is the amount it would push on a test rig, measured in pounds. You could also measure it in Newtons or other force measurements.
2. a )Yes it could. It has to to be certified. Don't forget that the aircraft is held up by its wings, not directly by the engines, so the amount of thrust generated need not equal or exceed the weight (force due to gravity) of the aircraft.
b) Don't know for sure and it would depend on the temperature and a few other things. It would definitely climb though.
c) Unlikely but it depends where you are. In most cases the SID could be followed, but in areas of high ground there are often "emergency turn procedures" which you would follow in the case of an engine failure. These ensure a greater terrain clearance, even though the SID might still be safe - the emergency turn would be safer.
3. 330 mins ETOPS does not yet exist as far as I know, but you can get up to some pretty wacky stuff on a test flight. After all, you need to test some thing you would never do on line operations.
Hope that helps.