I do see one thing that worries me though. It appears that you have reduced the overflow from 1.5" to 1.25" or maybe even 1". Since there is only one overflow, I'd be really worried about 1) amount of flow possible 2) anything (snail, etc.) getting sucked up and then lodged. I never reduce my overflows or put in hard turns (90 degree elbow).
Also, slightly worried about low water condition. Since the sump is in another room, critical to watch/automate top off and low water alarm if possible. If the return pump goes dry, many bad things can happen (Pump dies. CHiller dies. oxygen, temp go out of whack in tank, etc.).
But that's just the worrier in me. I'm totally impressed with what you guys pulled off. Have a drink for a job well done!