Tarot aces are powerful cards. Even so, I often think of them as similar to unborn children that, until birth and the unfolding of their lives are, pure potential as yet unknowable and unmanifest. In the Qabalistic Tree of Life, they are associated with Kether at the top of the tree which is also unknowable and unmanifest.
The aces represent the classic elements, Fire (Wands), Water (Cups), Air (Swords), and Earth (Disks). So, when one appears in a reading, as something unmanifest of course, you know that Fire elements are generally seen as creative and imaginative, Water as emotion and feeling, Air as intellectual and logical, and Earth as material and the body.
So, what we see at first glance is that the ace of a suit represents possibilities within the realm of its classic element that unimpeded end up as the princess of that suit. (As DuQuette says in his Thoth tarot book, we worship the ace and adore the princess.) Inasmuch as the aces are usually considered the roots/seeds of the powers of Fire, Water, Air, and Earth, the numbered–as yet to manifest cards–are contained within their aces rather than below them in some hierarchy.
As the initial potential on the Tree of Life exists within Kether (the crown or point) and is not manifest until the sephira Chokmah, the potential with an ace is not manifest prior to the two of the suit. The progression through the numbered cards is the same as the progression through the sephira of the Tree of Life. Suffice it to say, understanding the energy of each sephira as well as the paths between them, helps us understand the cards.
I agree with those who say that reading cards is primarily intended to help one develop his/her psychic abilities rather than predicting the future. Either way, I think a lot of readers have trouble with the aces because dealing with potentialities seems foggier than working with where that potential first arrived in the world we can see, hear, taste, and touch. That is, we see potential as uncertainty rather than a direction.
I identify strongly with the classic element of Air, most especially the knight (king in most decks), and appreciate the possible futures associated with the Swords suit. Each of us, I think, has a suit of preference. We know it intuitively. The challenge for the reader is applying the intuition that comes so easily for one ace to the aces of the other three suits.