Wordpress single site transform to multisite

I currently have a blog/website with over 500 posts and 20 main categories running on wordpress 3.4 with customized videozoom theme running on an Arvixe Business web Hosting plan
I would like to transform to a wordpress multisite which uses BP Forum & Buddypress
I have quite a few notes of what I need and have read up here , wmpu.org &http://codex.wordpress.org/Create_A_Network etc and have some practise with a fresh install of multisite
I would like to use subdomains e.g music.mysite.com.
All subdomain posts e. g posts from music.mysite.com must feed into the homepage http://www.mysite.com
All posts have a view count by day, week, month,year, all time - very important that this is not lost!
I have a few questions and insecurities. for example Will I lose links for all previous posts? Links that have been catalogued by google & other search engines facebook and twitter

Any support in these regards is more than welcome :slight_smile:

Thank you
Mark M.