Bible Verse division
In my opinion, this may be best approached as a sequence tagging problem, similar to part-of-speech tagging or named entity recognition. (So, this would be the seq2seq option, rather than regular classification). For example, think about it as trying to decide for each token, whether it is the start of a new verse or not.
The advantage of the sequence tagging approach compared to regular classification (at least when using some kind of neural architecture) is that you do not have to predetermine the length of the context taken into account for each distinct tagging decision.
To be clear, the classification approach (e.g, take 20 tokens to the left and 20 tokens to the right and decide whether the middle token is a verse boundary) is also viable, but the sequence tagging approach seems the more natural choice for me.
A final thought on the problem: Are you sure that (any kind of) classification/tagging approach is the right place to start? You may also want to think about this in terms of an alignment problem where you try to figure out which sentences from message edition correspondent to the ones in the NRSV version. Verse segmentation then comes for free. Alignment problems have been studied extensively in statistical machine translation.