No on the crushed coral - if you're going to do fish only with live rock in the tank, I would do live rock or rubble (smaller pieces of live rock).
I also would not overload the wetdry with rock - that will also potentially cause a nitrate/detrius trap.
Also, believe it or not, much depends on how many fish you plan to have, and what those fish are? Feeding habits, poop etc need to be taken into consideration
All very confusing I know, but you'll get through it.
Here is what I would need to help better guide you with my thoughts:
1) Size of tank and tank type (fish only, mixed reef)
2) Tank substrate (Sand, bare bottom, plenum)
3) Live rock? and how much?
4) Exactly what fish you plan to keep and how many
5) Any additional filtration info - Skimmer?? Size of skimmer?
Sorry to be a pain, but this is really good to know before giving advice.
House