1. - You are correct.
2. - Never heard of an adapter to mount RB lenses to an RB body of any kind.
If you look on KEH's website, once you go to the RB67 section and choose Fixed Lenses, all of the lenses in that list will fit all of the RB bodies. Lens hoods are cheap. If memory serves me, one lens hood will work for focal lenghts of 127-250. You will need a seperate one for the 65mm, which you can use for either the 50mm or the 65mm. You can get them very cheap, less than $10 US.