Till swoll’n with cunning, of a self-conceit, his waxen wings did mount above his reach based on this context, faustus is being compared to

I believe that based on this context, Faustus is being compared to Icarus.
In Greek mythology, Icarus was the son of Daedalus, who created a labyrinth where Minotaur was kept imprisoned. Daedalus and Icarus were too prisoners of the same island, and they wanted to escape using the wings that Daedalus made. However, Icarus flew too high near the Sun, and the wax on his wings melted and he fell to his death.

Walked would be the participle here. as it is a verb ending in -ed.