I was watching a video by Linus Tech Tips and he tested various anti virus software and he made a statement saying if you know what you're clicking you don't really need one. But also stated if you are downloading or going to shady websites then use a virtual desktop.
You could ask users to answer a question. But there will always be spammers, you've got human and them both scammers. Bot scammees are a little easier to manage but humans are almost impossible to stop. The best defense is approving each post.
No problem!
As for the browser I used Firefox developer edition. Which I find to be awesome, still haven't tried the browser you suggested because I've been super busy lately.