I agree with alot you said there Slides. It's not bad though that you write long lines, if they don't become overly generic with adjectives and adverbs. A narrative song sometimes needs long lines to tell a story, when a more poetic one doesn't. The problem with having long lines and then trying to sing, and not have them work is the fact that verses are usually written in four lines. So when the verse (music) plays though 4 times, each line (lyrics) should be sung over each line as it repeats. Seems logically but there's nothing wrong with breaking each line in half so that you end up singing half the original line for each line of the verse. Then use the second half for the second verse. Problem solved. This even becomes a benefit because leaving lines (whether musical or lyrical) incomplete and then resolve them later creates suspense (interest), a powerful effect in music. I agree less should be said at times so that the listener can fill in some blanks, but it may be more important not to block yourself from what may seem natural for the song. After-all writers block is sometimes nothing more than blocking yourself from letting your own ideas out or trying to conform them.

Leaving the melody out. I'd watch here. The melody is the most memorable thing of a song. Sometimes it's not what you sing but how you sing it. Just think of any classic tune (from the Beatles to nirvana, Floyd to Zeppelin), the words may be simple but it's the melody that gives them a quality that makes them memorable. If it's not melodic it's monotonous/talking. In verses and bridges you can occasionally get away with not emphasising a melody, but during a chorus: a melody is hard (near impossible) not to use and make work.