Yes, do as many as you can. As of right now that is one of the loopholes in googles ranking system. They do not penalize their own site. So you can spam it with as many links as you can to get it to the top. Just make sure to throw in some high pr backlinks along with it and some social shares to really give it a boost. If you are trying to rank in google what you need to do is do your search and see if you already see a video or two on the front page. If you do then you should be able to get yours there as well. If you do not see videos there already you may have a hard time. They seem to rank videos on certain keywords and not on others. You just have to test them out. I hope this helps.
I think you mean "drip" and not "drop?" The answer would be Yes if you are wanting to try and get it ranked in the search engines. I don't know if backlinks will help you ranking inside YouTube, but it can help on the outside. For ranking inside you should probably focus on views, likes, and keywords.
Yes, but do not overdo this! Just blast backlinks will not work unless they are some quality at least!
Yes. Drip feeding is great but it's not the only way you can rank your youtube videos. Other techniques such as: Commenting on related videos and adding a link to yours Driving a lot of traffic to it (whether fake or real) since Youtube system tends to rank website with the highest views very high are great.