If you do back the day before chest is it possible that you wont be able to push as much on chest day due to the fact that your back may be sore. It kinda makes sense considering your back helps stabilize on chest exercises
Do whichever is lagging more first.
What? Dude, that sounds like some sort of excuse. Do back, shoulders and legs before your chest. When you have weight suspended over your head / chest, you'll do what you have to... to not kill yourself.
If I wasn't sore when I go to the gym, I would think somethings wrong. Like my intensity sucks or I'm lifting like a pussy.
Maybe it will, maybe it won't. There's only one way you're going to find out and that's not by reading the replies to your post.
In my experience it doesn't affect me at all.