rock scape

If I understand you correctly - you're wanting to basically build a spray bar that would be in the back of the tank and send currents through various areas of the rock to prevent dead spots and increase circulation?

I know of one guy's tank where he took the return line from his sump, it was plumbed with PVC into his tank where at the bottom of his tank he'd built essentially a grid of PVC tubes. The tubes had holes drilled in them so that all of his return water came up through his substrate, like a natural spring. This prevented dead areas and circulated water really well.

 

I don't see why that would be a bad thing as long as it doesn't cause a spot for detritus to build up.

Have you considered a rockscape that doesn't need to have so much LR 'invisible' in your tank? Like something that doesn't have rock stacked against the back of the tank?