I think that would be tough.  Consider that if the YS/OW rulebooks actually existed in Jim Butcher's continuum, it would include a great many secrets that would get people -- starting with Harry -- in quite a lot of hot water.

Seems as though shrimp and oil ought to be significant factors...   

Considering how adamant Harry was at the end of Proven Guilty about not leaving any iron behind because it'd be rude to leave something so toxic just lying around I'd say that the NeverNever Safari trips wouldn't last long. Unless you were in Wildfae.

It takes more energy to raise something older (but said older things are more powerful and are easier to control). Harry said that getting Sue was like lifting an engine block, and that was on Hallowe'en, the day the barriers between life and death are thinnest. If Sue is an engine block, then I'd say a mammoth or saber-tooth of some kind would be like a motorcycle engine.

One element that I might use is the idea that when a mortal dreams, they create a temporary demesne in the Nevernever. If you're in the Nevernever, and know where to look, it's possible to enter someone's dream realm, and do any number of things. I'd guess that the demesne boundary would probably count as a threshold, though.

I picked up a bunch of replica medieval coins at a local medieval market back in may - and these are what we use for our fate points...and they actually fit quite nicely in the "fate" point spot on the character sheet   I'll see if I can't upload a pic of them when I get home.