We have acquired a 10 year old thin affiliate site, which ranks moderately well on semi competitive phrases, poorly optimized, which is being re-launched. It has no internal links. Improvements are in UI/UX - responsive design , improved on page and meta, new useful content [ small percentage versus scripted pages/semi useful ] and url structures, plus lightening fast load and rendering.
It has a legacy of some reciprocal links [ our pages taken down - also 404'd ] which have not been disavowed, as they are the only links into the site at this stage.
A while ago there was a good thread about the dangers of doing mass 301 redirects to the home page. [webmasterworld.com
...] . So ....
Does anyone have any experience in relaunching old sites from scratch using 404's on old url's. What are the expectancies with re ranking / indexing time ?