No worries for the long comment, thanks for the feedback! I'll respond to your list one by one.
1. We have no plans to allow players to change the note speed, as that's tied directly to the music playing and depends on its tempo. I think your other suggestions kind of tie into the problem you suggest (that it's hard to read the note timings), and we've been looking at ways to solve that issue.
2. Agreed on the ticks, we will make them coordinated and more visible.
3. After a year of testing we're unfortunately going to keep the columns the same. They're angled that way precisely because it makes the game more difficult, and gives an easy way to differentiate between our game and other rhythm games while also matching the background art.
Still, thanks for the feedback!