QA Testing before a website goes LIVE – We should be using 404 redirected, the plug-in for wordpress

Testing isn’t fun, I am going to be honest. I have to go through the entire site and make sure all links and buttons are in working order. I have found 404 error pages that leave a site sort of ‘broken’ and this is not good for google/SEO etc. So I found http://wordpress.org/plugins/404-redirected/ We should use this as a standard plug-in. Why not? Need to know thoughts here. Won’t this save us time? Testing must be accounted for in the Standard Timeline – it is TIME consuming – link, bugs, and more fixing adds up so we can discuss this more in workshops and in the overall schedule, budget and resource allocation.