I took 2) to mean, 'When I submit prior art, must I do so to challenge a particular patent? Or can I submit prior art for general consideration, in case anyone happens to submit a patent application to which the prior art applies?'
It would be cool if there was a database people could contribute to, but in theory the Examiner should be able to find this stuff in their prior art searches anyway.
The reality is examiners have a very small amount of time. Somebody has to do the work of verifying submissions, and making it reliable, and they don't have time to look through large sets of maybe unreliable data.
It's not enough to just submit an idea, you need the date the idea was conceived of, as well of some verification that this occurred.