About 1. and 2.: Scheduling is exactly for what you mention in your second point. The todo you are scheduling is grayed out on the current day and pushed to the selected day (the date you select in the mini calendar). It should normally appear there as a copy. Maybe you selected the wrong date accidentally?
In the preferences you can also switch on the option to add a date link after scheduling “Append links when scheduling todos”. Then you exactly know where you have scheduled it to and can jump to that day.
About 3.: Scrolling inside the calendar is an interesting point! Have noted it. If you have that many events, I recommend to switch off a few external calendars, if you got it distributed (see “View -> Calendar Sync Preferences”). Or you can decrease the font size a bit so it shows more (View -> Make text bigger/smaller, it will only affect the calendar font size)or increase the window size.