A couple of link wheel/link pyramid questions before i get started

1.no need of new seperate account
2.Yess

1. Some SEO experts say they like to maintain a general networks of web2.0 from which they build links to their money sites. Others create a new web 2.0 network for each new site. To cut the long story short - you can go either way: use your old web2.0's or build a new set for a new site. Be sure though not to link to your money site directly from all sorts of crappy sites (poor forum profiles, unmoderated blog comments etc.), but rather link those to your web 2.0's. I'd also suggest maintaining and developing your web 2.0's network by posting new articles to them from time to time.

2. Again, if you use social bookmarking for in-direct linking, it doesn't hurt to use the same accounts. If you link directly to original (!) articles on your site, you can use the same accounts as well, just do it in moderation. If you feel your accounts are overused, you may want to create a new set from different IPs. But there is no need to do that often. Many people don't bother with this at all, as they mostly use social bookmarks for indirect linking.