Identify a task that is a critical step or procedure in the organization, and learn everything you can about it, and become known as a specialist in that task. But keep up to date on the other functions of the company so that you are prepared to supervise it all.
That is not possible. You can however increase the chances of being the last to go in a lay off and that is by becoming the best at what you do. Work harder, smarter and become more of an asset than a liability. It's either that or marry the bosses son or daughter.
Well, since I AM the company, from CEO down to labor, I would say that yeah, I am pretty indispensable to it.