I agree with your take on Turzai. It seemed he was very much caught by surprise. He also ended up reminding the legislature that they should try to stick to interfaith prayers, so I don’t think he had any foreknowledge of Borowicz’s plan.
As for kicking off legislative sessions with a prayer, as an agnostic, I have no objections to it so long as participation isn’t compulsory. Though I’d also have no objection to the compromise you proposed, either.
But that prayer from Borowicz was so much more than just a prayer. It was a blatant political statement, and a totally inappropriate one. I’m quite relieved she’s not my representative!