Those screenshots are very helpful, as I can see what went wrong.
Vocals aren't quantized to the beat as guitar/bass/drums are, so if you are aligning your notes to a 1/16 grid your chart is going to turn out very poorly in-game. You will end up with notes that are early, late, and/or not the correct length, and this will be worse if the tempo is slower.
So, the first thing you need to do is change that 1/16 to 1/128 in the drop-down menu, and zoom way in so you can see every little line.
Then match your note lengths up with the waveforms - but make sure you're not including consonant sounds.
With slides, you don't want to just place a 16th note gap between every slide. The length of the blank space between the notes should match the length of time that the singer is transitioning between notes. So if you have an A to B slide, the first note should represent the length of time the singer is singing an A, then blank space where his pitch is changing, then the B should start at the point where he "arrives" at B.