yeah that one is kinda optional. If I have the votes I've found it to be worth it, though. I wouldn't say it makes the AI close borders on a consistent basis. And the effect is pretty big, especially if you are France.
Fair point, the flat multiplier to Holy City tourism would be really nice as France. Assuming you've been a fairly good boy too you can probably still maintain open borders, and you can still distribute Trade Routes as you need to.
Barring any Sacred Sites cheesiness, the fastest way is to race up the tech tree, grabbing every Culture wonder as you go. Use Aesthetics to go for the nice tourism bonuses, get your Ideology filled, and have fun.
I find it is still useful depending on map type to plunder a couple neighboring empires for Great Works though. When playing on Continents I'll go warmongering for as long as possible until we're about to meet the other continent: If I can pull off a couple Exterminations, that's fewer people I need to influence and it's more Great Works for me to start with.