I see where you're coming from, but it's a tough call, because using a synonym for interest/interests -- like "pastime", "hobby", "leisure pursuit" -- might mean sacrificing clarity or accuracy, and omitting the word entirely, for example, re-writing:

Interests are the things you list under "Interests" on your Profile Page as a way to find others on Dreamwidth who are interested in the same things you are.

as:

Interests are what you list on your Profile Page as a way to find others on Dreamwidth who are interested in the same things you are.

...could just be confusing, because the first question some people might have is: "Where do I list my Interests?"

(Yeah, okay, maybe that's just me.)

But have no fear! (El Zorro is here...) All of the FAQs are works in progress. Awkward and confusing language (yeah, like the stuff in this one) will be tweaked, and more and better FAQs will be added in the days ahead.

It goes without saying (not that this has ever stopped me) that during Open Beta, Dreamwidth is also a work in progress. (Which is not said to discourage comments like this, but, actually, to encourage them. And now I will restrain myself Very Firmly from making a Tom Lehrer joke...)