Nofollowing just sends the link juice into a black hole, so there's nothing to be gained from that at all.
Regarding the links... I'm not one to hoard link juice, but IMO, while links to coding standard sites are a nice gesture and might be appropriate if you were a large technical forum, they're otherwise not likely to be helpful or of interest to anyone.
I also wouldn't do global footer links to a great many social sites. I'd pick and choose the social sites carefully, and maybe use some sort of a social sharing pop-up, that conserves the number of outbound links.
Also, why link to these from home? You're wasting a lot less link juice social linking from articles, which is what you want to share, than by linking from home.