But she loosened her hair in the casement. His face burnt like a brand (line 32)
Now we're edging over the line from love to lust. Noyes keeps things clean, but we can feel that this little scene with the hair is all about desire. That's definitely related to love, but this moment helps us to see that their love isn't just a noble idea. It's based in a real connection between these two, a spark that's strong enough to make the tough-guy highwayman blush.
Had watched for her love in the moonlight, and died in the darkness there. (line 84)
Bess dies for love. That's the tragic and sort of beautiful idea at this poem, and it's really well captured by this line. Do you feel the arc here, the way the words lift up hopefully until "moonlight" and then drop down again into "darkness"? It's all very balanced, since "love" and "moonlight" are words of joy and possibility, and "died" and "darkness" are exactly the opposite. It's sort of like the whole journey of the poem wrapped up in a single line.