Thank you for the comments!
The stand is a foot longer than the tank because this is where all the plumbing, wiring and the trickle tower will go. This one foot area will be boxed in with matching wood for aesthetic purposes. The hood will extend over this enclosed one foot section to give it an integrated look.
I agree with you that the supports should be directly underneath the tank corners. I will add two single sticks of 2 x 4 directly underneath the unsupported tank corners to minimize any flexing of the top piece "ladder".
I appreciate the questions... I would much rather discover I overlooked, forgot or didn't account for something now rather that after everything is altogether.