In regards to the poem's structure, look first at its rhyme scheme and meter (scansion). The rhyme scheme reflects an ABAAB, CDCCD, EFEEF, GHGGH pattern. While the rhyme is very structured, the meter is not so strict. It is mostly iambic tetrameter, meaning that it has four feet per line (tetrameter), and mainly an unstressed/stressed beat (iambic). It varies slightly from this meter, but if a reader listens to someone read the poem aloud, he/she will hear the stress on the syllables.
In regards to specific devices in the stanzas, here are several examples.
Stanza One: While this stanza does not contain any significant sound devices such as you mentioned, it does rely strongly on inversion (unusual word order). Notice lines 2 and 3.
Stanza Two: Assonance does play a key part in this stanza. Frost uses many short As in words such as grassy, passing, as, having, and had. Similarly, "wanted wear" in line 8 is alliteration.
Stanza Three: The rhyme of stanza three also represents "A" assonance with an alternation between long and short As.
Stanza Four: There is "ll" and "g" consonance in this stanza. See shall, telling, and all, and repetition of ages along with diverged.
Since your question focuses on sound devices, a good argument can be made that Frost chose his sounds, words, structure, and rhyme to represent a more conversational tone. His poem certainly appeals to the common man, someone who has to make an important decision at some point in his life.