It's impossible to say at this point. The burden in your case is the same in all other criminal cases, beyond a reasonable doubt. There is no one piece of evidence that is considered better than any other piece under the law. If, after considering all the evidence including the video, the jury is not convinced either the crime occurred or you were the person committing it, then they'll be instructed they have to find you not guilty. You need an attorney to review your entire case and give you their best legal advice.
Yes, the dashboard cam video can come into evidence if a proper foundation is laid for its admission. This is no given. Aside from these devices, people are taking videos from PDAs, surveillance videos and all sorts of recording devices. But, as Mr. Greenwood says, they are only part of a criminal trial. Your prior record works against you in several ways as well. You need a good criminal defense attorney to deal with the evidentiary issues and aggressively represent you.
Sounds to me like the complaining party is BSing. If it isn't you, it isn't likely that it will appear similar enough to you to secure a conviction unless, perhaps, you have a twin brother. It is much more likely that the video is unrecognizable or non-existent.
Answering your questions on this forum does NOT constitute the forming of an attorney/client relationship. The opinions rendered herein are based on general principles of law. Laws vary from jurisdiction to jurisdiction and there are often numerous factors which can render advice or an opinion inapplicable. You should NOT make any decisions about the handling of a legal matter based on any opinion posted on this forum. Rather, you should directly consult with an attorney about the particulars of your case before making ANY decisions.