and dead link is one of the most crucial killer for UE. how to figure out and fix dead link in our sites? following are the steps i use most, hope it can give you some ideas.
1, check whether there is a dead link in our sites frequently(there are lots of SEO tools can do this work)
2, before the loading of new page, using page building tool check the links in it.
3, without a delay to delete dead links once you find them.
4, build 404 page, redirect to it when dead link happens.
5,using robots text to shield the visit by spider for some pages.
those are the ways i use most, if you think there is some thing wrong, or you have more effective way, please share with me.