Question

Is there a way to import custom SVG shapes clipart directly into Dia

Answer 1

If you are fine with compromising advanced transparency it will be possible for sure.This what you need to do:

1) Drag and drop the SVG file into an empty drawing area.

2) Export it as .shape:

a)File -> Export...

b)Then select "By extension" and save the file as .shape.

c)Then a dialog will appear. Choose the default size in there.

3) Import it: F9 -> NEW -> SVG Shape (select the file)

And this should do the job