A month ago, I created a poll where I asked people to rate how much time adventurers might spend doing somethign productive that was not adventuring. Although this poll only got about a third the responses as my Player Abilities poll, I still think it is worthwhile to analyze the results. Feel free to leave a comment, or contribute to the associated discussion thread.
It's important to note that the results were fairly spread out. "Might Dabble in Other Activites" was the most popular, but only received 36% of the votes. Five of the seven categories received 10% or more of the votes. Only "Dabbles as an Adventurer" and "Adventures Reluctantly and Rarely" failed to get 10% of the vote.
Another way to look at it is that two-thirds of respondents see adventuring as a character's primary occupation, while the remaining third is split evenly between those who see adventuring as a secondary occupation, and those who see characters splitting their time evenly between the two.
A third way to look at it is that 90% of the respondents felt that adventurers do spend time doing things other than adventuring, and more than half see that aspect as significant (part-time job or greater).
So I would say the game should assume the adventurers primarily adventure, but should be open to ways to address other occupations. That may simply be a section with narrative advice, robust themes that incorporate part-time professions, secondary skill charts, or even -- as much as I loathe them -- craft, perform, and profession skills.