Nice looking sump. Hope it works out for you. If I were in your shoes, here is what I would do:
1. Remove the ceramic stuff on the entry side. they hold detritus and will cause more harm than good. also, 1 blue filter floss pad should be sufficient. it will trap a TON of YUCk and will clog quickly.
2. Why do you have a filter sock for the skimmer outlet? this is completely not needed.
3. while the slits in your end cap will prevent the pump from picking things up, they are too small in my opinion and may clog un-necessarily and will restrict the inlet of the pump. I would scrap that and either go with none or drill a bunch of holes. maybe 1/4" or so diameter.
4. your Ro/Di filter seems to be missing a cartridge. IMO, you need: 1. Micron Filter, 2. Carbon Block, 3. RO membrane, 4. Di media. (in that order)