Here's my opinion
1. I wouldn't let lack of results discourage you. As an undergraduate, your potential is not basedon what you produce so much as your process. How do you approach research: do you ask good questions, find some way to test your ideas, execute in an orderly fashion, etc. Your professionaism (showing up, foillowing through, wiriting up results, critiquing ideas, etc.) demonstrates your abilities. Show ambition, curiosity, good technique, etc.
2. The second problemis harder. As an older, non-raditional student, I see that younger students often don't yet have the interpesonal skills, or the confidence (or the diesire?) to make themselves visible. Yes, you need to have some one-on-one time with professors to get really good LORs. That's a reality. You would find however that professors would be open to more time if you are good. If you ask an insightful question, show real desire, etc. As a whole (of course there are exceptions), these guys know the game and have seen hundreds of students come and go. So they know a good one when the see one. But taking this shot has risk - so if you go for more one on one time be prepared with something that will help your cause.