I am dealing with an ecommerce site that is 15k pages and over 8 years old that was Pandalyzed and now does about 40% less in traffic year over year.
We decided that the best thing to do was to start over with the site, do a redesign, improve the info architecture, do layout fixes, add new original content for some important pages, etc.
There are tons of things to consider when doing this. Among them are baking into your new design as many best practices for your industry as possible. Another is to add social features where applicable, such as Twitter and FB buttons, and oh yeah, Google+ buttons too. And you need to consider which pages, if any, are you going to 301.
Re-designing a site also gives you the opportunity to consider moving hosts, changing your url structure, maybe adding subdomains, changing your analytics provider, and more.
This site I am redesigning got hacked a number of times over the years, and the host is so bad that no one answers, ever, when you call support so you have to leave a voicemail that doesn't get returned.
So, needless to say, I am moving hosts with this redesign. My two questions are:
1. Is there a threshold for number of 301's? I don't want to or need to 301 all 15k pages, nor would I think that is a good idea. But how many could I do without causing Google ranking/indexing problems? 10%? 50%?
2. If the domain registration does not change, but I change the host and the entire design, would also changing the ownership of the Google Analytics trigger Google to think it was a new entity taking over the site and reset it's power/juice/rankings?