eiseverywhere.comは安全ですか？

No privacy policy. This site is used by multiple conferences for marketing and registration. Providing personal information without a privacy policy means they can use it however they see fit. Even if conference X has a privacy policy, you aren't submitting your information to the conference, you're submitting it to eiseverywhere. That results, in my mind, to trust issues and trust issues create vendor reliability issues. So I agree with the low ratings. It would be trivial for them to address these issues, they apparently don't care.

rating a site with almost 100,000 visits based on three comment, two obviously disgruntled,makes no sense. You should remove your rating until you have many more scores. This site is used by many business organizations for the purposes shown above. I suspect the site itself does not know about the negative ratings and would contest them. Your value to me for rating unknown sites just declined. This site has none of the problems that should lead users not to go to the site.