1, 2, and 3 are probably easy. 4, not so much.
1. Default auto-scroll pre-roll: just like having a defaulted auto-scroll duration.
2. Allow for setting pre-roll and auto-scroll duration on the web UI - I'm not actually sure what the "Duration" parameter on the web UI does, or how (if?) it interacts with the auto-scroll on the device. So maybe consolidating down to a single set of parameters (auto-scroll pre-roll & auto-scroll duration) used consistently everywhere would be better. Ideally, they could be overridden on the device, so individuals in the band could adjust as needed without affecting others.
3. If the latter part of item 2 could be done, then by using the terms consistently between web app and iPad, the actual times could be displayed consistently also.
Now...dreaming here:
4. Speech recognition is getting very good. True, in a noisy environment like a band it might be tricky, but it would be very cool if the app could listen for when the first line starts, and use that as an auto-scroll trigger. Done perfectly, it could actually be used to trigger paging or scroll pace automatically. This would allow for greater automatic flexibility of intro lengths, solos, etc.