IPad – Blackboard theme for iPad Keynote

Staying with the keynote format, no. I you export to a QuickTime movie, you will have the best chance to preserve the slide deck as it was on the Mac when saving it alone doesn't work.

You can only work around this by getting the mac pixels on the iPad since this appears to be an inherent limitation of the iOS app as written today.

Have you tried using Air Display to add the iPad as a second monitor and tell Keynote to present on the iPad? The company does awesome work and like any screen sharing over a network, there is latency and/or slight rendering artifacts, but it's better than other apps in that space as any I've seen.

In Keynote.app: Select all parts of the graphic you need to scale, then copy them to the clipboard (Command-C).

In Preview.app, just create a new document (Command-N). Contents from the clipboard will be automatically inserted. Save this document as PDF somewhere, and drag it to Keynote. This should do the trick.