payments.ebay.comは安全ですか？

Ebay is a great way to find sometimes GREAT values on goods and to get money back out of things you no longer need, and it's probably the safest way to make a purchase when using a PayPal payment on a PayPal insured ebay auction transaction. However things go, your money is covered, and PayPal has a faaaar better data security record than do most retail stores. Just be certain to choose a username for your account which doesn't make it a trivial matter for blackhats to identify you.

Mostly a positive experience. Statements can be custom generated, and information is fairly well organized. There are a couple of things that might take you by surprise, such as an unwarranted chargeback that can lock up your account and make it so you are unable to pay someone. This happened to me once. There is no easy workaround. The chargeback was a fraud and later withdrawn, but I had to live with the nearly two week inconvenience of a locked account. Still, overall, they do a decent job.