1) There seems to be no allowance for adjustment of image area printed when a print crop is applied. If the original aspect ratio is 2:3, an 8x10 cuts the sides equally with no way to "move" the image around in the LR print module; it must first be copied in the Develop module and then the aspect ratio for each cropped print applied to each copy. If you have a single image that needs three or more print sizes (all different aspect ratios), you are bogged down. Now, multiply that by 100 images...just for one event. And when you need to create a web gallery and export the finished files with the original aspect ratio...all on deadline...this is a major problem.
2) There seems to be no way you can easily (or perhaps at all) center images on the page. For example: try dropping a 6.654x10 (native size from the D3 series) image exactly on the center of an 8.5x11 cut sheet. You can't do it without dropping the length less than ten inches, and the procedure is clunky as well. I use precut custom mats for some of my print work, so this is a real issue. This is easy to do in Windoze.
1. If I understand you, once you crop the image into a size within the print template in Custom Package, you can move it around within those boundaries. You have to turn off “Lock to Photo Aspect Ratio
“. Then move the boundary box the size you wish. Command/Control drag inside to move the image about to “crop” it to the boundaries of this cell. So you can make the cell first and season to taste moving the photo around to fit that aspect ratio.
2. Should be able to center an image. If you want to resize an existing cell, holding down the Shift key while resizing the bounding box will constrain the ratio of the cell, and holding down Alt/Option resizes from the center point instead of the corner.