Intellect Devourer Host wearing Armor, Arcane Failure Chance?

[Snow_Tiger]

If an Intellect Devourer wizard or sorcerer is in a host that is wearing armor, does the spell failure chance apply? Or does the intellect devourer have room to move its hands to cast spells inside the host's skull????

[OmniMage]

I don't think an Intellect Devourer can cast wizard or sorcerer spells without risk of arcane spell failure. I think it has to either use the host's body to cast spells (and suffer the limitations of the body), or leave the body and cast spells itself. The description doesn't mention that it can perform such a task (cast class spells while within a skull), but it does mention it can use its spell like abilities (while in a skull).