Why the veil?

[Minyatur]

How is there free will in higher densities without the veil?

I think we should have part of our 3D life under a veil, and then have the veil taken away when we're old enough (if we desire), and have motivation to work.

Or when we despair, we should be able to peek through the veil.

You already do have permission to peek through the veil. You are the only thing that can keep yourself from doing it.

All I have to do is let go.

Or perhaps uncover the mechanisms that prevent you from accessing beyond the veil and your own desires that manifests them.

It is kind of hard to work out as much of your true self is hidden within your unconscious and is there for you to uncover. Ultimately there are most likely things to let go of, but the roots of them are for you to seek within yourself.