Agreed. Zero-drafting or what I call it "death" drafting is not recommended even though there are gains with it. The problems as mentioned are safety, lack of forward visibility and at those speeds some cars may not be able to negotiate the distance safely.
Better method would be to use distance drafting or at least give some distance (3-4 seconds) if you're going at highway speeds. Obviously it really depends on the situations but from what I've read and experienced it's just safer to give yourself some room and you'll still get some benefits of a lead blocker.
Also with HM, you're better off going slower or less than 60 (depending on your car) due to aerodynamics and the engine gearing. I know with my Scion she's very frugal at 50mph.
I know there has been a lot of negative press with HM and death drafting and when Wayne Gerdes (who coined the "hypermiling" term) says "NO DON'T DO IT - NOT SAFE", I gotta agree with the man. Plus there are other ways to squeeze the petrol that don't put you or other drivers at risk. Oh and welcome!
Here's a
topic that addresses the issue of drafting: