I'm in the process of move a website for a client, utilizing a new theme. Usually this is straightforward enough but some of the base 'category' URLS they use are mess and they would also like to be able to change some of the names of those categories also.
I know fixing/changing these URLs can be accomplished using a 301 Rewrite but I am wondering if there is a possibility of any issues arising from doing so.
The client is overly anxious about broken links and loss of ranking and I want to put my own mind at peace about the changes. (Granted I know that modifying URLs may affect ranking).
Also part of the change will be setting the site with a prefix of WWW - i'm assuming the same concerns apply.
Thanks for your help in advance.