Need advice, selling on Ebay for other people.

I've got two Ebay IDs, and have sold some items for other people - family, friends, etc.

But...they often don't tell me much about the items, and I'm not an expert in some of the stuff. So there have been a few problems. Other issues is keeping the money straight, its difficult to sort through Ebays billing lists to figure out what it has cost to sell an item.

So I'm wondering what you have done in these circumstances?

So far I've set up a new ID and have bought a few items to build up some feedback.

Here are some of my direct questions:

Should I charge a fixed percentage?

Should I open a new Paypal and bank account to keep the financials separate and simple?

Should I rent a PO box to keep my personel address out of the mix?

What do you think about listing an item for friends, but letting them ship it?

Not expecting to list a lot of items, but have to do something to keep this stuff separate from my auctions.

Thanks in advance, Jett.