I have no difficulty creating speech bubbles and pointers in PhotoShop, and then saving as PNG for a transparency. I can insert the items as Picture-in-Picture with no problem, edit position, and preview. When I play the movie back in iMovie (not burned yet), not only is the transparency gone, the original movie is jerky. Does this correct when burning, or is an impossible thing to make?
Karsten wrote up a user tip for this
https://discussions.apple.com/docs/DOC-4021
An important thing to remember is to create your PNG in the same aspect ratio as your project. If iMovie has to crop or letterbox your PNG, it converts it to JPEG and you lose your transparency.
Another option would be to make a still frame from the movie where you want the speech bubble, and use this in PhotoShop to create the speech bubbles or pointers at the exact size an location where you need them. Then export out with only the transparency and speech bubble/pointer layers in the aspect ratio of your project. Drag it in to your iMovie project and choose CUTAWAY rather than PIP.
How to create a still frame.
Ah, thank you. I forgot about the aspect ratio.
iMovie 11: Speech Bubbles, Pointers
