I'm curious what you think the earth looked like during those billions of years. Scientists have pretty concrete ideas of what things were like over time: where the continents were, which species existed at which times, and so on. Do you think they are right about these things, or is it all just guesswork?

When I was younger I thought that evolution was false, but I started to change my mind once I started to think about that kind of concrete question. If the dating methods are generally accurate (and I am very sure that they are), it follows that most of that scientific picture is going to be true.

This wouldn't be inconsistent with the kind of design that you are talking about, but it strongly suggests that if you had watched the world from an external, large scale, point of view, it would look pretty much like evolution, even if on a micro level God was inserting genes etc.