I have these too and they are designed to give your foot the barefoot feel.
My first couple runs i over did it (over 3 miles) and i got bad shin splints.
I would recommend running 50/50 between these shoes and normal running shoes.
I don't think they were designed to be used but for a few miles a week as a complement to your normal routine. In that case, your reccomendation seems to be pretty valid. I just bought some Nike Free 7.0s last night. We'll see how light running goes on them.
As a slight aside, I've found that interval running has helped my 1.5 mile time (excuse my Navy input into this Marine PFT sub-forum). And I have only done the interval thing on a treadmill. Any thoughts?