I am a bit confused on orc magic still, despite reading the change notes (and manual, which is outdated on this) 3-4 times. Let me see if I can ask the right questions.
1) From what I can tell the magic codexes are needed to go from dreamwalker to a named magicuser caste (druid, etc.) Various places also say that a codex teaches some spells but not sure whether that remains the case. Is it? Or are mojos required for all spell learning now? I don't see an option to learn spells without mojos, so it would have to be part of the actual promotion process, but no idea how to tell in game.
2) Can plain dreamwalkers learn spells from mojos and use magic staves? If so, what's the benefit to going to the advanced caste? (If the answer to 1 is the process of promoting to advanced caste teaches a subset of the spells... needs to be made more clear in the manual or somewhere.)
3) I think I get that any caste of magic user can use any staff or dreamcaster now. Is this correct? And ammo is simply a choice of two type that are matched to two of the staves each. Then that ammo can be further enchanted according to the limits for that type of ammo.
I think the confusion comes from all the recent changes and no concise restatement of how it all works. Too much conflicting information in change logs and manual to keep it straight in my aching head. :p
Maybe I'll just give them all hand cannons and let them make their own steel or brass magic.