You can use event.preventDefault when draging and dropping or a touchHold so that way you can have both scrolling and dragging/dropping.
Trick is to bind mouse events with touch events.
Double tap is tricky, but totally doable, here is one that worked for me.
When you use a double click event just add a doubletap event for that.
This way you can use doubletap, drag/drop and enable scrolling when not touchHold or drag and drop.
UPDATE: If you have a .draggable element, you can easily get the drag to initiate auto scroll by using a scroll option of scroll: true.