Yes, I agree. I use a touch screen device daily for this reason.
Mobile phones with full browsing support and Touch Screens change things really.
If you're really serious about it, why aren't you asking us about things like microdata?
H1, H2, H3 isn't really needed if your doing HTML 5 <header>/<section>. That's even better.
Except that search engines do not hit the images as much, and since speed is one factor in Google's ranking, and having a higher content:markup ratio has to help in that too...
I'll argue the image height & width though. Without it, too much page jumping going on. Especially at slower speeds, or those with latency/server issues. Every little bit helps...
Even when the specification explicitly says they should be empty for when they are used in non informational contexts, e.g. bullet point images?
Alt attributes are still needed, even though they are not a requirement for HTML 5 Doctype.
And? That's relevant how to this part of the discussion? I'm aware of that limitation, but from a purely 'search engine optimisation' point of view it doesn't make so much difference. SEO by definition is making the content more accessible to machine readers, often at the expense of real users.
Again, mobile phones, ipads, some netbooks, will not cache or even load most images over 25K.
So you're telling me that you can magically make a forum *measurably* better in search engine rankings without dictating the content to users?
I completely disagree with about 80% of what was said there.
See, to be honest, that's just "I disagree but don't have anything to back up arguing why I disagree"...