Suggestions:
1. You could start your own tread for this as stand alone application. It deserve it.

Yep, this deserves its own thread.

2. The exported objects have a default transparency 0.8. You could add a transparency slider.

Yes, definitely a slider or spinner (x.xx precision).

3. "Launch Shape Designer" button give "...ShapeDesigner-2.0.0.exj does not exist!". You could pack it inside of this application.

Yes, pack it with the Generator.