Mitch,
The lack of dodging and burning capability in Aperture is a bit of loss, but it may not be as easy to achieve. In PS, the dodging and burning is pixel manipulation on files that have had the images set (PSD, TIFF, JPEG). In Aperture, and LR also I believe, there are no direct pixel manipulations, but instead, instruction sets about how to process the RAW image for output. Most of the controls appear to be sort of widespread, such as within a channel or encompassing the entire image. I say most, as the Patch and Retouch tools, as well as the Red Eye fix tools appear to operate on a more localized part of the image file. Not sure how that is managed, but if you think about it, there should be some way to adjust the channels on a more localized portion of the image file, and that is what dodging and burning essentially is....decreasing/increasing the exposure levels in some selected region, and by some selected amount. This sounds simple, but I am not sure how easy/hard that is to do in creating an instruction set. The pixel replacement (Patch/Retouch and Red Eye) may be easier, as that works under a specific set of conditions, whereas Dodging and Burning is a bit more regional than local on the file.
Not making excuses here, as I really do not know how the changes are made. Personally, I would love to see those capabilities added, as well as another that looks quite impressive.....regional adjustment. The U-point technology that is being used in the Nik Software Viveza plug-in is an example of this, but that process is creating a layer mask on the fly, which has not been seen in Aperture or Lightroom that I am aware. If there is some way to create that sort of adjustment layer as an instruction file to apply to the RAW image file, rather than a pixel manipulation layer file, which is what it appears to be now, I think the problem would be solved. Now THAT would be a very nice additional tool set for Aperture, and it would afford a huge range of tuning offerings, such as gradients, both local and general. I keep hoping for this.
As for the vieiwing sizes.....that has been an issue in Aperture from the start. The only answer seems to be related to the Loupe tool, but that only encompasses a small area, and not the entire view. I have gotten used to switching between Zoom and Full Screen view to evaluate parts of images, but there is no true 50% view for some sort of more routine viewing and adjustment. Not sure it would be hard to add, but it is not there presently that I have seen.
LJ