Hi there! Welcome to the land of tequila and doing it in the road. I love questions about the game.
Quote1) does anyone restrict the Feeder Need to demons, say, power 10 and greater? seems to me a chump change pocket watch Object that does nothing but cloak wouldn't be to keen on swallowing Asmodeus or somesuch...
I haven't restricted anything so formally, but yes, my general experience suggests that Feeder demons are also big demons. That might have been a cop-out though - as I've observed and carried out many times, a well-constructed demon at Power 6 or so is tremendously more than a match for an ill-conceieved pile of abilities at Power 12. So maybe the Feeder = big idea is more a matter of laziness than necessity.
Quote2) does anyone require a Feeder to eat a certain total power of demons to meet their Need? such as a Power 10 Feeder neeeding to eat, oh, say, at least 10 Power in demons a week to prevent the Sorcerer from summoning that previously mentioned chump change watch and all his swiss made cousins and not really going out on a limb and calling forth some critter that might actually eat the first one, then turn towards the Sorcerer....
H'm, well, the Feeder idea falls into the Very Stupid category (from the sorcerer's point of view) from the get-go. It's a ready-made crisis, all the time. After all, to the sorcerer, he got this demon to
do something, not to run around feeding it and cleaning up after it all the time. And when feeding it is guaranteed to piss off a ton of other people and demons, well, you might as well paint a bull's-eye on your forehead. As if that weren't enough, the typical Sorcerer setting is actually pretty rare in demons, so just finding them is a huge problem right there.
All this is to say that any version of the Feeder is a problem way above and beyond the typical problems of a Sorcerer character. Making it even harder by requiring more than one demon-meal to make the Feeder go "burp" ... well, that seems pretty painful to me.
Best,
Ron