What the soul is doing is kind of walking through the forms, and so our experience of thinking isn't normally this kind of pure intuitive insight that intellect gets, and that intellect must get right, because it's always identical to its objects, it's always the same as the forms that it's thinking about.

We do each have an intellect but there's a universal intellect which is the same for everybody, as it were. And this single intellect is grasping the platonic forms.

I'm sure that Plotinus wasn't that impressed by the Christians.

The importance of Plotinus is not only his own philosophical ideas which are quite interesting, but his historical impact as the founder of neo-Platonism which is the main philosophical tradition of late antiquity.

The soul must be distinct from intellect because even at its best, what the soul does when it's thinking, is it thinks linguistically, it thinks in a temporarily extended way, so it for example, might go through the steps of an argument chain, as if you were going through a syllogism and seeing that something followed from the premises, whereas intellect simply grasps the forms.

The body distracts your soul.

Assuming there is an intellect, we're clearly not this universal intellect or we would know it. So that's one function of soul.