I use BigCommerce, and they have a system where all the URLs are dynamically generated from the name of each product. So if I named a product "widget x y z" the url would be /widget-x-y-z/, and if I changed that to "blue widget x y z", it would change to /blue-widget-x-y-z/ and automatically redirect the old one to the new one.
As a result, in 6 months, because of a lot of tweaking and experimenting, I've ended up with a hefty list of 400 redirects. Some of them are very old, and some are recent. So my question is in two parts:
a) does having all of these redirects hurt my rankings?
b) if so, would deleting them help?