thanks for feedback!!
save actually does save
and for export its for exporting the entire project then u can load it from another device easily
for the drag part i think there are tow solutions either removing dragging and just adding the node you want with a popup or adding popup with dragging (because double clicking for dragging is godots scrollcontainer limitation)
for arrows i guess i didnt describe it correctly its more of a pen rather than an arrow (maybe they should be separate features)
btw have you tried the built-in image editing ?