So how does he know they're so great then? In academic career progress contexts, citations are what matters. If your 'great' papers have 2 citations, they're objectively not great - in fact, they're pretty shit even. They might become 'great' next year, time will tell - but making a case of how great a researcher you are with a paper selection like that is, well, not very smart.
No, not true. He's arguing he's an asset to the university, and one of his arguments is his publishing track record. In that context, there are two way papers are 'good': they are published in Nature or The Lancet, or they have high citation counts. Whether a paper has the potential to get lots of citations doesn't count for anything. Likewise, if the content is super out of this world great, but nobody has cited it - the paper is shit.
In all sorts of other contexts, obviously there are many ways in which something can be good. In the specific way he used it, there is a very well-defined and objective standard, and he fails it.
Why do you hate this guy? In most areas of computer science, certain value of publications is attributed to the venue where they are published, which isn't necessarily science or lancet. His RV work got the best paper award, which is a good indicator of quality and potential. The other two papers are in reasonably good venues.
I think that his publications record isn't great, and that and his personality are perhaps what lead to his tenure's outcomes, but that's not a point you are making.