1&2-the faders on a tablet or iPad don't have the resolution for accurate adjustment. Trying to mix on those is going to be an exercise in frustration.
3-just my opinion(and feel free to ignore it
) but I think you are using your eyes too much, and you ears not enough.(I know folks that will turn off or cover their screens so they don't fall into this trap)
Beyond that, to make minor adjustments, it might be faster to either show volume on the track and drag the volume line up or down(using the Ctrl key for "fine"mode). If you grab the line past the end of the song, you can drag the entire line(start to finish) and keep any automation moves intact. Or opening the last plugin on the track and tweaking the output level