Google will only give you one of those top spots if it's for a search term that Google feels can be best answered with a video... or if you have very low competition. If you see videos on the first page of the Google search for your term then you have a good shot. Hard to tell without knowing your exact keywords, but just ask youself "does my video make sense in this SERP?" Like "How to" videos do good because that makes sense, to give someone a visual of how to do something. But like let's say your search term is "florist in Chicago" ... not a great search for a video to rank in. Google usually gets this right IME.

If you think you have a shot for ranking for video you can build links to the video URL just like you would for any other site. Social bookmarking is not typically enough.

As for your second question: No, Google owns Youtube, they will figure it out heck they probably know what you had for breakfast too

Thanks for your help, I'll try to target my keywords for both youtube and google now :-)