"# Listening to speakers refer to an inanimate software construct as "this guy" without getting distracted. " - So no "Hi guys", fair enough
"Not being the special case ("hi guys and girls, I guess, too, if you want to get really technical about it!!") " - So no "Hi guys and girls", err..
The difference between "hi guys and girls" and "hi guys and girls, I guess, too, if you want to get really technical about it!!" is that the second sentence goes out of its way to call attention to the Other-ness of the marginalized group. But why not circumvent the issue entirely and use a gender-neutral term like "folks", "everyone", or (depending on the formality of the occasion) "distinguished colleagues"? It perplexes me that people who have no trouble writing a compiler or debugging device drivers apparently find it so difficult to phrase a simple sentence in a way that doesn't exclude anyone.
Hofstadter makes the same point (that words that claim to be both gendered and gender-neutral are never the latter) in a less snarky way in Chapter 7 of his book _Metamagical Themas_, entitled "Changes in Default Words and Images, Engendered by Rising Consciousness". You can find it on Google Books.
I wouldn't generalise too far off this list, though. It looks like an amalgam of things that annoy different ladies. I only picked out 5 of them that I agreed with.
Although I say "Hi Guys!" sometimes when greeting my wife and daughter, so I don't really see what's so offensive about it.