yes, I think your strategy is right.
It’s good that you’re running an A/B test on the price for 1 week. (you mentioned that you have changed your price for a few hours and sales dropped – you can’t draw any conclusions from a few hours – that is just too short)
As Amanda said, keep your images for now if you didn’t see any negative impact. The increased sessions is positive (your main image must be better).
Then once you’ve finished testing price, work on your bullets. Keyword stuffing is not good – you need naturally flowing sentences that speak to your ideal client. Module 8 will give you lots of great guidance and ideas on how to best optimise your listing.
A+ content is a good idea but wait until you’ve completed your other optimisations before starting that.