I feel like this thread's basically become how texting has ruined dating. All these rules and anxious moments could be dispelled if you simply put down the damn phone. I realize it's harder than it sounds, believe me, and it wasn't until the girl I'm seeing disabused me of my propensity to hold entire conversations via text that I realized the value of, well, less is more.
We've consistently only texted to set up actual dates. Sometimes we reply immediately, and sometimes we give it 24 hours. Because these aren't conversations, and I'm asking about Saturday on a Tuesday, it really doesn't matter if she gets back to me immediately. I'll say that, now that we've navigated five dates, she sent me a picture of her birthday cupcakes today. She was up front with me: she told me she hated texting initially, and so my expectations were lowered. I now love this approach. Maybe send a picture of something interesting or link an article: that's better than trying to do small talk over text.