> HD cards are only supported in 2D applications by MorphOS, right?

Yes. There was a TinyGL beta version with 3D support for TeraScale2 GPUs (R8xx/R9xx minus RV970), but an update removed this support. It's supposed to return, together with TeraScale1 (R6xx/R7xx) support, though.

> Or is Wazp3D also possible with HD cards?

In software rendering mode, yes.