A few things:
If you need to send more money than you have available in your paypal account, it will take it out of your checking account or credit card (whichever you choose) when you send the payment. No need to import funds then send payment... it can all be done at one.
Paypal has never protected me under any circumstances. The only time I got my money back from a bogus transaction was when I had used a credit card and called VISA to nix the payment.
My buddy uses hammersnipe and loves it.
However, you have to give them your ebay ID/password (obviously). Uh, I'd rather not give out my passwords for people to access my credit and other personal info through My Ebay.