A few things here -
Crushed corals are a form of Aragonite (calcium carbonate - CaCo3) Aragonite is measured in grains. Aragonite sand I've never heard of but would just be smaller grain particals of aragonite not sand. The smaller grains are more friendly for sandsifting goby's and jawfish no real issue for most of your fish - exception may be the Eel's belly but admittedly I have zero experience with morays.
KH of what ?? I had to pull out some old arse test kits to find that value - most reefers prefer dkh not ppm or meq/l . Your DKH is in the 6-7 range very good for fish, for future reference I keep my reef @ 10 DKH or 179 ppm if your hobby evolves.
1,400 GPH is alotta flow - kudos! most ppl skimp - I'd rather see 2x 650's on opposite sides of the tank, it'll give you betterin-tank agitation, but that's just me.
10ppm Nitrate is also extremally good for a newer tank - keep monitering it and don't be suprised if the nitrate builds in time, it happens - too aviod that issue you could use Purgien or Chem-pure in your HOB.
5 Damsels/clowns - I wouldn't do it but if it works for ya - at least the snowflake has future fresh food swimmin' around
I also question the LR pounds too - it doesn't look like 70lbs to me either, maybe 20-30 lbs tops might want to re-scale them prior to the 55.