I'd wouldn't allow that one based mostly on my preferences as a GM. I'm usually reluctant to just take away something that the player obviously invested some value in and could be central to their character. Which is not to say that I won't, just that there should be a really good story reason and I don't think they come along often enough. I really don't know the rules though, so if they disagree with me...
I think this is something of a moot point from a player perspective anyway. No matter what the players catch is, it is not likely to come up unless there's a story reason for it to. In Werewolf: The Forsaken people don't just randomly carry around silver bullets unless the story gives them a reason to have them. And the most obvious example, if a player plays a white court vampire, their catch is unlikely to EVER significantly come up in game, unless the story requires that someone deliberately tries to exploit it.
PC's always get the long end of the stick in the "weak point" area. Not that that's a bad thing. A Catch SHOULD only be exploited when the story calls for it. Having a badass power that gets negated frequently and randomly isn't fun.
but the weakness inherent to the Item of Power ability is that it isn't your power and can, in theory, be taken away. Now that doesn't mean they lose it forever (and if they do, they should also get the refresh back), but you can lose it.
Hell, Micheal lost his item of power in the very first story he appeared in.
But thats kinda off topic from the thread. The question was whether its possible to use feeding dependency or Items of power as a Catch.
Upon looking through the books I'd say no on feeding dependency. As all the vampires have it tied to their toughness/recovery and still have full catches.
For Items of Power I'd say yes. Infact that is exactly what Nicodemus has. His Noose gives him Physical Immunity, with the catch that the Noose itself can harm him.