Theocritus' seventh Idyll, Philetas and Longus

Few years pass without an attempt to interpret Theocritus, Idyll 7. The poem's narrative and descriptive skill, dramatic subtlety and felicity of language are mercifully more than adequate to survive these scholarly onslaughts, so I have less hesitation in offering my own interpretation. The poem's chief problems seem to me to arise from uncertainty as to: (a) Who is the narrator, and why are we kept waiting until line 21 before we are told that he is called Simichidas? (b) Who, or what sort of man, is the goatherd Lycidas, whom he encounters on his way from town to the harvest festival? Answers to these questions fundamentally affect our interpretation of their exchange of songs, which occupies almost half the idyll, and of Lycidas' gift of his stick to Simichidas; and these interpretations will go far towards interpreting the poem as a whole.