A quick question,
after taking 10000 hrs too SHARE,
can I leave the site while video is being moved to the stream server?

Once the page changes to your dashboard and says it's sending to stream server you can close the tab/page, shut down the browser to your hearts content. Just make sure to check back for it being ready to publish, it can take anywhere between a minute to 20 or 30 minutes depending of the size of the video.