Hi Craig,
1. To display the column chart side by side: I have created a feature request on this and will update you as soon as the feature is implemented.
2. The width and depth of the column is not same: Thanks for bringing this issue into our attention. This issue has been fixed internally and future release of the product will include the fix.
3. To make the 3D graph not semi transparent: You can adjust the transparency by varying the alpha value of the BrushInfo class using which the Interior color is filled. Please find attached the sample which illustrates this.
F41502.zip
Please let me know if this helps you.
Thanks for your interest in Syncfusion products.
Regards,
Geetha.