[iojam]

bonjurkes,

First question here : For adding sitemaps to google, it requires valid google account. But the script is only pinging google. So will it also work? or must i also add my sitemap manually by using my google account.

The google webmaster account submission is optional (although still a good idea to track sitemap status)

Second question: At my forum guests can see threads but when they want to read its content, it asks for login info. So must i enable showthread and showposts functions or must i disable them?

You should definitely consider to allow showthread content reading for the guests (and so for SE bots), otherwise there is not so much to index at your site for search engines.

Third Question: I submitted it to google and it said downloaded 1 hour ago but at script there is a show sitemap download log and when i click it there is nothing displayed.But google says i downloaded it 1 hour ago. Why it isnt displaying?

I suppose you've submitted the sitemap files as forumsroot/vbseo_sitemap/data/sitemap_X.xml.gz, while the correct URL is forumsroot/sitemap_X.xml.gz.