Yes, yes, yes and yes.
As a footnote, I signed into my Overstock account that had been sitting for half a year to find a nice credit on my account. Several I know are having success there.
Yahoo is rumored to be joining with MSN. Could be good..never know. It's free to list on Yahoo..that's a big plus.
Bidville it appears to have the most items up..more visibility to your items.
Yahoo accepts cvs files as does bidville. Overstock is getting ready to use cvs files which is a big help!
There are several others..I'll place here tomorrow.
It's late in FL.