They can be out ranked. It depends on the competition and value outranking will bring as to weather it is worth the time though. It sounds like this answers page is ranking purely due to it's assotiation with Yahoo Answers.

Yes. Easily.

Yahoo Answers pages usually rank high due to having no other page more relevant to display first. Think about it. Yahoo Answers content are just regular people asking questions and getting answers. There's no strategy in the content, and it's not as useful to somebody as a 500 word unique article that addresses what the searcher is looking for.

Write up a page for the keyword and optimise it as best you can, push some links at it and I guarantee you'll be up there with 'em.

Good luck!

Normally people use their website as the source for their answer. But make sure you make a relevant answer and not just say something like: "just follow the link I posted so you can get the answer..." yahoo will remove your answer for answering like that.