Eastern Red Cedar(ERC) is not a true cedar but a juniper(J. virginiana). It will make a good bow. I have made a few but one, an ELB style bow, blew at a knot. Hickory backed ERC is supposed to make a very fast shooting light in hand bow.
In my shop I have a 49" ERC stave roughed out that is 1/2 heart-1/2 sapwood that I am going to sinew back it at some point in the future.
I believe ERC dries relatively fast but if you can wait a year you will have a better stave to work with.
For an ERC selfbow, I would back it with rawhide or silk just for giggles.