aged domain

I have a domain that's now 2 years old. The original plan I had for it was to build a community around a product that's name is in the domain. I setup a blog and a forum and there's some content, but I never stuck with it, so it never went anywhere and has PR0. I've since come up with a plan...

I have a domain that was previously owned by someone else, is this good in as far as the domain is now 'aged' when I bought it - or does it only work per owner/registrant? Domain became lapsed, bought it from godaddy.

Hey guys, I have a domain registered at May 2010 and it got sandboxed since the beginning of Sep 2010, I continued to build backlinks using article submissions like UAW for more 2 months after that but it didn't recover so I just left it there, and it's still sandboxed. Recently I have...

... but I didn't know it had been registered before(there was no reason to check), anyway in the seoquake toolbar it shows as 1st registered 10 years ago but there are no backlinks or indexed pages. I have used wayback machine and google and other stuff and they show 5 pages for 1 year, 8 the...

If I buy an aged domain (maybe with keyword or without) and redirect it to a newly registered domain (with keyword), can the new domain get authority and other benefits of the aged domain ? I bought a domain newly, but my competitor have domain with 10+ age. My SEO-person told me that it is...