A few notes (pun):
You could save yourself some hassle if you open both your pitch guide track and your vocal chart track simultaneously. Select them both and open them on top of each other by using CTRL+ALT+E. The transparency will allow you to see where you "should" be as you chart the vocals. ALT+N will swap between tracks. Could save you a lot of time.
You need to be scrubbing a lot more. Scrub, scrub, scrub. Simply lining up the vocal tube to the length of the waveform doesn't make for good vocals. Lots of noisessssssss the human mouth makesssssss don't register as pitch. I try to only have tubes placed where a clear vowel sound is being made.
I can't stress the importance of slides enough. Lack of slides punish good slash drunk and enthusiastic singers and force the vocalist to sing like a robut. No fun. For example, that initial "fantasy" absolutely needs a slide. I was hoping you'd add it as I watched when you went back and gave it a listen
At first I was gonna tell you that using the 128 grid brush is silly, but for a song with a BPM this slow, 128 is actually somewhat necessary. However, under normal circumstances (say, 120 BPM), it will make very little difference. I used to chart everything as "finely" as possible in 128 then realized what a waste of time it was. 64 will become your best friend once you realize what's important to tube and what isn't.
I love this song and was thinking of charting it someday, so once you give it your best go, I'll be happy to take a peek at your project and make sure it's up to snuff. The best way to know if it's up to snuff is to actually perform it in Rock Band. And you're right, it's always preferable to have too short of tubes rather than too long of tubes. Hit the mark, don't fill the tank!
Very useful video for beginners and those who don't have a knack for doing things "by ear." My only criticism is SCRUB SCRUB SCRUB SCRUB SCRUB.
Oh, and use these scrub settings... that -30 30 is super important.