Now about that DCT4000
Yay! I've finally gotten all the leaking issues solved! Now, just the pump speed problem. (DCT4000, so quiet, so strong and I love the gradual start!)
Here is the sump with pump and skimmer off and the overflow chamber empty. I do have some room so if I need to add another gallon or two I could without overflowing the sump. I took the skimmer cup off so more of the plumbing is visible: (um, just ignore the floating float valves, sock holder, and random sponges...)
Here it is with pump and skimmer on. At this point, the water is still higher than the 'over' baffles but the top of the pump is exposed and starting to suck air. The pump is set at it's lowest level. I didn't include a valve in my plumbing because I figured that's what the adjustable speed was for!
At least the overflow is silent.

These are the pipes that came with the tank. Is this a good water height or should I shorten the durso pipe and drop it down? Would dropping it help with balancing flow through the sump at all? (I'm thinking less water volume there, more water volume in sump?)
I'm considering what to do here to have more balanced flow between pump and drain:
1) Do I just need to add more water to the sump? Since the water level is still above the 'over' baffles, I feel like that's a no. I might be wrong.
2) Add a valve? If so, where? Restrict flow or redirect it?
A)I could cut the horizontal pipe and add after the union and just restrict flow without redirecting it. (And maybe include more unions on either side of the valve for possible cleaning? Would that pipe then need more support?)
B)I could add it and an elbow where the T is capped and redirect flow into the sump. (I feel like that would definitely need more support then.)
C) I don't really have space below the T and between the pump because I have a 1inch threaded x barb adapter to 1 inch tubing, then a 1in-3/4in reducer to 3/4 tubing to 3/4 adapter to the PVC pipe...eventually making it's way to the 3/4 bulkhead.
At least I'm learning a lot...