There are a few things that bother me a LOT
a) Smarter shape creation, from the (+) in any shape: If i have a shape and i press the + button y creates a new and similar shape. Good. If i want to create another one, it superposes or is shown behind the first one. Just place it elsewhere!
b) Arrow Line path: To be able to modify the shape of the path of the arrow. not just the beginning or the end
c)Arrow Line path properties: Hey, i want to move the origin point of the arrow. I click on the arrow, and the properties show up IN FRONT of the point of origin.
PS: Just copy FigJam's UX :)