Hi Insertsomethingfunny,
Thanks for bringing this up! There are plans to add an offset to the notes to compensate for input delay, but that may not make it into the demo until a later date. As for the amount of lanes, there are only three lanes used on Easy, and four lanes on Medium! Though it may not be as obvious as it should be, since all 5 are still displayed (─‿‿─).