Len is right up the road from me, so I'll head up to him for a new module some time in the early summer once things have calmed down some around my house.
Then you are one lucky gentleman. Len will set you up correctly.
My wife is due to deliver twins in a month--which will mean three boys under 3 yrs. old
Congratulations. But, I don't know if even the word "hectic" could describe what your house will be like...
Hanging the bow is fine...though I suggest dusting it off before shooting it.
Instead of the nail though, why don't you pick up one of those screw-in bow hangers for treestand use and just screw that into the wall instead. It is rubber coated already, like you mentioned, so you don't have to worry about scratching up the idler. They cost all of about $1.00 a piece.