Obligatory

You can't predict human behavior and they may not care past a certain point. You've got to see how they're going to look at a situation and even throw in a hint or two such as a random spot check on the guy from say, the elf in the party, who may or may not feel that the guy is trustworthy through just gut instinct.

If you want to get other ideas on a campaign, you should also read Young's Mar Tesaro tale, which is a full campaign and some of the pitfalls of what may and may not occur in a campaign.

That sounds pretty good. One point though:
is exactly what I meant when I talked about background checks as a matter of course. At face value, it's pretty good advice, and when your players don't think to take it any other way, they go down one branch of the plot through no decision of their own. Some ideas for hints would be:

- include a minor details in Jerod's story that doesn't quite seem to fit
- arriving at the orc dwelling they see the girl more or less happily playing with the orcs rather than be locked up somewhere
- the PCs might know from stories or prior encounters that orcs aren't necessarily evil savages
- easiest method: maybe the guy with the highest passive insight simply gets a funny feeling about the job

Any one of these is worth investigating further to wary PCs without requiring the PCs to actually automatically be wary of anything anyone ever tells them.