Sorry pennine hillbilly, I can't help with all of these. Rhubarb is poisonous, so you are right to grab it out of their mouths. Raspberry, bramble, in fact all fruit bushes are fine to feed. Holly is ok actually, not poisonous, but of course not all goats are brave enough to try the prickles.
We feed ours flowering currant- don't know it's proper name. It's one of the first things out in spring, and for a sick goat just after kidding its nice.
Feed the usual things, elm, elder (not the berries generally), comfrey, sycamore (before July), chestnut, ash, birch, willow, nettles, sticky willie!
Beth