Diabiolists / Demons praying or speaking holy names aloud

Do diabolists fear or have any difficulty praying aloud or speaking the name of god (e.g. Yahweh, Jesus, Jehovah), the names of saints, or touching holy items or relics?

I read ROP:I a while ago and I don't recall if this information is clearly stated or not.

By the same token, can demons "fake" prayers to God for the purposes of deception?

AFAIR, no. Only demons have. And I think it's one of those activities they can do after having spend 1 confidence point.