Ok, I think my second question does not make sense. You don't need to assign all your dice to your weapons, right? In any case, I have a similar question about the Red Crown: If the criteria is met, do I suffer the harm even if I don't attack? Also, do I apply the effect (bonus and harm) every time I attack? Thanks!
1. Writher doesn't place one in a space that already has a pod.
2. Like you mentioned, you don't have to assign dice. If you can't hurt anyone with the spell, or the crown's effect wouldn't be triggered because you aren't dealing harm, then you don't suffer the negative consequences. You apply the effect once per round.