Content [create/edit] sharing in multisite

HI there

there is little performance issues if we have all modules at same installation. basically I have a site social, and i like to offer many facilities to users, but if i install many modules on same installation it impacts the performance, so i decided to user multisite,

for e.g.,

songs : songs.example.com
videos : videos.example.com
groups: groups.example.com
blogs: blogs.example.com

something like that.

now, I have to let the users to manage the other site contents with in the same site (main site), I mean, in users profile page(main site) needs to display his songs & videos and also it should have all the facility [create/edit/comment] without going to the subdmains,

Is it possible? or is there any solution for this?

Thanks in advance.
Vinoth