FWIW, I broke down the numbers a while back and it may be helpful to know that
A) that 3.4 ypc suffers from small sample size and
B) it is still superior to what Vereen did after week five last year, by a healthy margin.
I wouldn't read anything into Cadet's rushing history.
Also, Dion Lewis may have been cut a couple more times than Woodhead, but I feel like your post overstates (perhaps unintentionally) the gap between the two. I suspect that, if it weren't for Hard Knocks, Lewis would actually appear to be the more impressive of the two at the time of acquisition.
I'm really not worried about the receiving back position. It seems highly probable one will be OK and, as you say, Bolden is a reasonable emergency option.