I have a site which has a good page rank but i need to change its domain name due to legal issues, last week i found the perfect replacement for it and its owned by someone that is willing to sell it, my only concern is that the domain this person is selling me has around 15k pages indexed in Google but the url structure is a real mess, pretty much no hierarchy to let me change it easily with the htaccess and bottom line im not willing to keep those pages as part of the site. As i said earlier my main goal was to get this domain regardless of the indexed pages it has, my question is the following: If i buy the domain but don't recreate all those urls in my new application and i just let them go to the error 404 will i get penalized by search engines? or thats fine and those results will just drop which is not a big deal for me Thanks in advance for the help
Yeah you can let those URLs get a 404 error page and let them drop if you don't want to recreate those pages, you won't get any penalization for that. You might also consider to include a link to the homepage from the 404 page (just in case).
Yea, you could setup redirects on the 404 pages, but ultimately, you shouldn't be penalised. Eventually the search engines will pick up your new pages and discard the old ones.
I agree above Google really looks for live links and if your pages arent opt correctly I think the worse thing could happend would be loss of page rank