It is great to see that you are able to use it to accelerate your training. 
DALI is still under active development (and technically still in beta 1).
The team is currently reworking the whole architecture and working on some major missing features (such as pointwise operations).
A few notes about the operators you mentioned:



 makslevental:

for example I really would like to be able to normalize without cropping


I know it may seem a little bit counter-intuitive but you should be using CropMirrorNormalize 1 (minus the crop and mirror options). The DALI and CUDA kernels have compile time mechanisms to reduce the runtime overhead (to none).
We may add an Normalize op in the future but it would still use the same kernels under the hood.



 makslevental:

to change imagetypes outside of the decoder


You can actually do it with the Cast operator.



 makslevental:

or resize but after crop


I guess you mean Crop after Resize.
This limitation comes from the fact that Crop and Resize operations are (sorta) commutative, but performance-wise it is better to first crop first to not apply the interpolation algorithm on a data that will be cropped anyway.