Try checking out JAMF's user boards or the Mac Enterprise group. You could always use Symantec, comes with malware preloaded as a feature.
That can be patched.
ClamXav is also open source. Some may say that is a vulnerability in itself.
There's only so many ways you can answer the same question. If you want different responses, ask different questions.
Most respected by whom? Certainly not by everyone.
You apparently didn't read and comprehend the links. Sophos introduces a vulnerability that isn't present with other antivirus apps, such as ClamXav. You can't "patch" the fact that Sophos runs with root privileges, something that could be exploited by malware. That vulnerability, however significant, is not introduced by apps like ClamXav.
That can be patched.
ClamXav is also open source. Some may say that is a vulnerability in itself.