This scene is packed with little metaphors, similes/comparisons, etc. which shouldn't be too hard to find. I'll put some of my observations down, though.
As you suggest, the wall Romeo leaps represents the hatred between the two families. Moreover, the act of leaping represents Romeo's transgression of standards.
The orchard itself could represent a number of things. I vote for The Garden of Eden & forbidden fruit.
Romeo describes Juliet at the rising sun; "it is the easy, and Juliet is the sun. / Arise, fair sun, and kill the envious moon." (sc. 2 l. 4) remember the scene takes place at night/early morning, like most of the most important scenes in the play. Effectually, Romeo is saying that Juliet is the force that transforms night into day. Also, perhaps not intended, there is a sexual metaphor; one rises (wakes up) by the sun. Since Juliet is Romeo's sun, he rises to her (i.e. gets an erection). In any case, for Romeo, the power of language transforms the world. This is then juxtaposed in the same scene when Juliet says: "Tis but thy name that is my enemy. / Thou art thyself, though not a Montague. / What’s Montague? It is nor hand, nor foot, / Nor arm, nor face, nor any other part / Belonging to a man. O, be some other name! / What’s in a name?...