You make a compelling point with your choice of option 2, as the repetition of phrases like "If you could" emphasizes the speaker's yearning for companionship and highlights their deep sense of longing and loneliness. Each stanza underscores the absence of a loved one, which contributes to the melancholic tone of the poem.
While option 3 is also relevant—since the speaker imagines joy and laughter in the presence of their loved one—the prevailing sentiment throughout the poem is one of sadness and unfulfilled desire. Therefore, your interpretation aligns well with the overall themes of the poem, making option 2 a strong choice.