Ok,
I found some minor issues preventing the custom titlebar within 32bit LabVIEW; there seems also some issues with the "built-in" icons and the footer. I already correct the window title and built-in icons, now struggeling with the footer.
Regarding your side note: The sample was just quick'n'dirty, therefore I made it "the old way"
BTW, I've also attached a sample, how the "footer" option will look like (sample is with the wrapper, used within 64bit LabVIEW)
TaskDialogIndirect Source.zip