Can they be eaten raw?
Yes they can but they are very acerbic. The kids eat them sometimes but I will warn you the birds are often first to get them even when I am watching. A net like you use for blueberries might help.
Elderberries are local and there are a couple varieties but there are also two 'types', one which is not edible. The ones which are edible bare fruit in a lacecap type formation. It if its a foamy cluster, like False Solomon's Seal its not edible except to the birds. Elderberries are known to very high in antioxidants and are good for reducing swelling in the body. They make an amazing jelly and beautiful wine.
I will have to look into St John's. I got mine from a local greenhouse and wish I'd bought more.
I also have what appears to be a semi-paralyzed chicken now. I believe she was struck by a car. Its the only reasonable explanation to me. I think her pevis has been damaged as she is sort of able to walk but can not hold her tail up and sort of drags her back end now instead of standing upright. Its sad because she is the only Breda I have and I really wanted these. I have had them before and she's the only one to hatch out. Sweet birds, really nice, and they lay a whopper of white egg compared to their size, so with no comb to speak of they work out really well here for my colored basket... until they have an accident like this.