While it is certainly a good thing to teach actors that there is a difference between poetry and prose, one must be careful in how one approaches lines. They're not all alike and, especially, they are not all to be treated as syntactic or semantic units.

One must attend both to enjambment and to end stops and, in blank verse, to caesurae. If anything in the reading of the line draws attention to its line-ness, the reading will fail. That is the flaw in most reading of poetry, both professional and amateur.

The line is a poetic unit, and must be brought out poetically, with careful attention to rhythm, meter, assonance, alliteration, punctuation, and meaning. Lineation is merely the scaffolding that makes everything else work.