Sounds like you have done this before!
have you considered swapping the cw recovery with either the amon ra or amon ra style recovery? the latter can restore cw or ar nands.
The reason I suggest it is because I am familiar with it, and it is also suggested alot in here. mainly because it is reliable and does a good job wiping in preparation for flashing and such like.
Your cm7 rom may just be taking a while to fire up, but I suspect that perhaps you could have done a bit more wiping before you flashed it.
I would suggest loading the amon ra style recovery, wiping well, cache, data and dalvik cache, 3x apiece, and flashing the rom again.
Also, don't forget to flash the Gapps file as well. It is needed with that rom, I think.
I have gotten away from cm 7 because everyone I have encountered who has suffered the bootloop of death has been on cm7 and a tiamat kernel. I have enough problems and the idea of that just puts me off.