“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 a good conversion rate (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.
Our recommendation is that you slowly test and tweak your listings over time. You can do that using software such as Splitly.
Another option is our Amazon Product Description Boot Camp video series that will help you with creating or tweaking listing titles, bullets, descriptions and search terms.
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.
If you want to proceed, we can offer instructions for implementing the various parts of the new listing gradually and watching the results after each test. This does not guarantee that a negative reaction will not occur, but it may help lessen the impact.