Maybe you could explain the question a bit better. Googlebot is their indexing tool which feeds computers into their systems. I'm sure that it is a different process altogether that calculates backlinks.
Submit your website to Google so it indexes your website and places them in results. You can learn more about Google Bot in this help article.
I disagree. The age-old rule is *not* to submit. It has always been better to get some backlinks and let g-bot discover your site on its own. This lends credibility, IMO. Like courting a women, let her come to you!
But some people feel more secure if they've submitted and the penalty will be negligible. However, we still don't know what the OP's question actually meant.
I'm not sure if they are using bots in getting the back links... you can look at your webmaster tool to see your legitimate back links.
I would be very surprised if googlebot wasn't a single purpose tool. I think it will just be indexing and feeding raw data into the servers. Another process will take charge of the analysis of sites.