“My existing listing is producing steady sales now, but I want to try & make it better. Could completely rewriting it hurt my current success? ”
Yes, it could. If you have existing sales already (without using promotional discounts or freebies), it is possible that having the entire listing recreated and uploading it all at once might cause an adverse effect.
Any time you remove everything Amazon is currently using to rank your listing, your rankings will suffer. This is because of the way listings are indexed by Amazon. In fact, making minor changes will trigger your listing to be reindexed. Sometimes this results in nothing more than a temporary blink that is barely noticed while other times you see more of a drag on traffic/conversions.
Marketing Words is a copywriting agency. We do not have the staff (or frankly, the desire) to test, tweak and implement copy changes. Marketing Words does words. That's our superpower.