你的理解都不错，但译得比较拘谨，

你的理解都不错，但译得比较拘谨，不很象诗。原诗写得很不错，除第二段和第三段最后那句，其它都是八音节，四音步，抑扬格，句句押韵。如果我们翻译，虽然不一定能做到跟原诗一样，但应该尽量努力接近它。当然意思还是主要的。在意思准确的基础上，尽量做到形式优美。

We Wear the Mask by Paul Laurence Dunbar

We wear the mask that grins and lies,
It hides our cheeks and shades our eyes,—
This debt we pay to human guile;
With torn and bleeding hearts we smile,
And mouth with myriad subtleties.

Why should the world be over-wise,
In counting all our tears and sighs?
Nay, let them only see us, while
We wear the mask.

We smile, but, O great Christ, our cries
To thee from tortured souls arise.
We sing, but oh the clay is vile
Beneath our feet, and long the mile;
But let the world dream otherwise,
We wear the mask!