Thanks Jewel. The upgrade is looking to be a long way off still, so at some point I will likely rebuild my overflow pipes in PVC and swap them out. The sump is definitely hard to work in but gets the job done.
As for the lights... I feel that they are just about right!!

They can always be dimmed down of course but I haven't had any issues with bleaching. I was at Bigshows a week or two ago and I felt that my tank had a similar colour and brightness to his DT which was running an 8 bulb T5 I believe. Subjective observation of course.
I'm actually thinking of adding more light TBH with a single DIY T5 unit at the front and the back of the canopy, either side of the LEDs, rocking some kind of actinic bulb like purple plus or fiji purple.