connect it to ur bank account = sending echeques (5-8 business days to clear)
connect it to your credit card = instant payment
paypal protection is geared more towards the buyer than the seller
if the shipment is done via USPS first class international or australia regular post, you could potentially fraud the seller by launching an item unclaimed dispute. you will win, coz the seller cant show proof of DELIVERY. proof of shipment is not enough. as item may be lost via post.
thats just an example of the unfair buyer protection paypal has and the most common fraud using paypal.
on the other hand, if the seller doesnt send u his/her item, and u paid, and the seller cashes out his money from the paypal account, u may not get ur money back either.
also fraud can happen with unconfirmed buyer accounts (buyer credit card billing address different to shipping address), buyer can say the credit card purchase was unwarranted, and then the money willl come back to the buyer's account.
paypal is a subsidiary company to ebay, they charge fees on most transactions, but none to the person making the payment. fees only applies to the person receiving the money depending on wether the seller has a premier/personal account and the source of the payment (credit card or paypal balance).
Paypal also charge 2.5% extra for currency conversion. thats alot btw and usually more than what ur credit card provider charges.