It's high and it's mighty. It's everything that the poet-acrobat rests upon in terms of his work and purpose. At the same time, it's high so it's full of danger and potential mishaps. That wire is everything to the poet, because it will take him to Beauty, who's waiting at the other end. But it also is the very thing that keeps the poet in the mindset of "constantly risking absurdity." The poor guy just can't win, whether he's risking it all on the high wire or trying desperately to catch Beauty. After all, he knows that there are no guarantees.
Lines 7-8: Not only is it high, but the wire is also not far from that slippery rime. There's nothing easy about his performance. It's also of "his own making" so there's no blaming anyone else if the poet/acrobat happens to fall to his figurative death. We see that word "high" repeated a few times in the poem and it always hints at the idea of the poet's work being a sort of "high art." It's not for everyone, but it's also the poet's responsibility to at least try to make it accessible to everyone. Maybe that's why the whole process is so slippery. Meanwhile, that "sea of faces" is watching the poet, maybe waiting for him to fall or waiting to be inspired. All eyes are on him.
Lines 13-15: To top it all off, the poet is performing those "entrechats" which are surely making his job even more difficult. But hey, it's all for the show and it's what he's there to do. Sure, "sleight-of-foot tricks" sound tough, but that's the job. But since they're "tricks" we can't necessarily trust them. Maybe they're telling the truth, maybe they're not, which reminds us that the poet here isn't necessarily a truth-teller, but a performer. And yet. One of his high wire acts is to perceive things for what they are rather than what they may not be. So it's not all fun and games. There's some real work to be done.