Can I easily change my site to be part of wordpress.org?
Hi Georgie,
Can you give me an idea as to what you mean by "part of WordPress.org"?
You can see the differences between WordPress.com and WordPress.org on this support page:
http://en.support.wordpress.com/com-vs-org/
I would also like to use google webmaster tools.
Sure! You can setup Google Webmaster Tools with your blog by following the steps here:
http://en.support.wordpress.com/webmaster-tools/#google-webmaster-tools
for the wordpress stats, can they help me how many unique users I have?
We track page views as opposed to visitors. You can see more details about the stats we track for your blog on this support page: