First, with whomever you deal with, be absolutely honest. Explain what your strategy is. It's entirely possible you'll get an agent to show you the property anyway. They'll figure, perhaps correctly, that you might like the home so much that you're willing to make an offer on it now. Or that you won't succeed at auction, but will be interested in using their services for another property.
As for whether to make that request of the listing agent . . . I'd advise against it. The listing agent represents the seller, not you. In many areas of the country (I don't know about California) it's entirely legal for an agent to represent both parties. And, with full disclosure, it's perfectly ethical. Still, as a practical matter, it doesn't serve your interests as well as having your own agent.
As for paying a fee: Sure, that's a possibility. Whatever agreement you and the agent agree to should work.
Bottom line: As your instincts suggest, don't mislead the agent. Be absolutely honest. But I'm sure that you'll be able to work something out.
Hope that helps.
Do your homework on what the rules of the autcions are, when can you inspect the home, when can you back out if you find something going on that is not acceptable.
Just because the home is scheduled to go to auction, doesn't mean that it will. So if you really want the property you should work with the agent (or one of your own choosing) so you have access to the property; so you know what you are buying; so he/she can represent your interests in the purchas; and so you can have inspections to discover exactly what conditions exist.
Auctions are for the professional investor, not the uninitiated. You should be smart here--find an agent to represent you and make an offer that your are comfortable with. If your offer fails, you can always try again at the auction.