I like your changes. A few suggestions:
Copy can always be changed. After all, there’s no such thing as perfect copy. You can always improve it (this is why testing in small batches is such a great practice).
You can make this more active and shorter. E.g.:
Perfect copy doesn’t exist. Excellent copy evolves over time.
Make small changes to your copy and notice how sales improve with each change you make.
I believe you’ll see that sales curve start to take flight.
You don’t need to say “I believe” as it reduces the impact of your statement. Try using the imperative instead:
See that sales curve start to take flight.
PS Seems that there’s some inconsistency between testing the small batches and being bold? You might want to choose to go for one or the other.
If you have time, have another go this week?
Enchant readers. Woo customers. Win business.