(1) An individual's political philosophy depend on his ethics, which depends on his epistemology/metaphysics. If by ethics, epistemology, and metaphysics you mean explicit philosophy, this view is inapplicable to most people. Explicit philosophies tend to be mere rationalizations: self-conscious window dressing draped over the cognitive unconscious, which does most of the heavy cognitive lifting and does not think in terms of broad philosophical abstractions. Moreover, the genesis of explicit philosophies generally suggests that the causation tends to go in the other direction; that is to say, people tend to begin with a political philosophy, which they rationalize with various ethical rationalizations. Epistemology and metaphysics are usually ignored altogether; but when they are brought in at all, they are almost always brought in last. This is true even in Rand's case. Her early writings are dominated by politcal and ethical concerns; only later did she begin to dabble in metaphysics and epistemology
Now one way to skirt around these objections is to contend that individuals have "implicit" philosophies in which the political depends on the ethical, and the ethical on the epistemological, and so on. Everyone, Rand contended, has a philosophy; and if they don't have an explicit philosophy, they must have an implicit one.
The trouble here is that Rand's view of how implicit philosophies are developed and formed is heavily influenced by her false view of human mind. For Rand, an individual's implicit philosophy is formed by premises that have been integrated by the "conscious" mind:
Your subconscious is like a computer—more complex a computer than men can build—and its main function is the integration of your ideas. Who programs it? Your conscious mind. If you default, if you don’t reach any firm convictions, your subconscious is programmed by chance—and you deliver yourself into the power of ideas you do not know you have accepted. But one way or the other, your computer gives you print-outs, daily and hourly, in the form of emotions—which are lightning-like estimates of the things around you, calculated according to your values. If you programmed your computer by conscious thinking, you know the nature of your values and emotions. If you didn’t, you don’t....
The quality of a computer’s output is determined by the quality of its input. If your subconscious is programmed by chance, its output will have a corresponding character. You have probably heard the computer operators’ eloquent term “gigo”—which means: “Garbage in, garbage out.” The same formula applies to the relationship between a man’s thinking and his emotions.
As I have stated repeatedly, there is no evidence that the human mind works like this, and an enormous amount of evidence that it doesn't. Human behavior, whether political or otherwise, is not determined or strongly influenced by broad philosophical premises. Whether those premises are explicit or implicit is entirely irrelevant. Rand got this wrong in a very big way and it has enormous implications for her political philosophy. For Rand needs this doctrine to make her political philosophy realizable. In order for Objectivism to achieve its political ends, political philosophy must depend on ethics, which in turn must depend on metaphysics/epistemology; because if this is not so, then Objectivism becomes politically impotent.