Communion questions

[Beorne]

I've read the very long thread on communions but there is something I don't have unserstood well yet.
1- If a communion master casts, for example, body ethereal, the slaves are affected too?
2-Other masters gain buffs benefit too?
3-Is this true even if the caster casts the buff before entering in communion?
4-Is The master fatigue shared only between the slaves?
5-How the fatigue is distribuited if the slaves casts some spell?
6-Does the slaves gain the magic bonus too?