I am a member of sci.astro.amateur google group and posted a link to one of my astro article pages as a discussion moot point. This attracted visits from the group members. Already my site has a page rank 2. Will posting more such links help improvement page rank of crestvideos.com ?
If the traffic of Google Forum has low bounce rate than, it will definitely help to increase PR of your website.
No, it wont. It is like just another referral to your website and has equal effect as some one is coming from other website. SO gain more links from relevant website to increase your PR.
I don't think PR is a big issue. PR is all about backlinks. If it affect the ranking factor than why low PR pages appear before then high PR Pages.