I'm planning to go a large Earth Science conference (couple thousand attendees expected) that does not result in refereed publications. Some other fields (like Computer Science) have conferences that result in publications, but I'm in Earth Science and it's extremely rare our conferences result in publications. Only journal publications really count.
As a student, I have unpublished results that I wish to obtain feedback/input on from experts in the field. But if I present unpublished results, what's to stop someone from stealing my work and publishing it in a journal?
For a different project I'm working on, I published my results in a paper, but I wish to obtain feedback for further work. However, when I submit a conference abstract, I need specify what percentage has been presented or published elsewhere. I hear that if 100% is specified, the abstract will likely be rejected. So it seems presenting published results is unfeasible, while presenting unpublished results is risky (Question 1). So now I'm confused: what do most researchers do?