Whats the deal with Live rock

[Reefersutherland]

Okay so I am very new to the reef world, infact I am newer than new because I dont even have a tank set up yet. lol anyways I am going to do a 90 gallon (full reef) with built in overflow and probably a 20-25 gallon sump filtration system complete with protein skimmer (the octopus ones get a good review by most ppl on here... thoughts?) and bio balls maybe a UV filter also (maybe not we will see... thoughts?). I currently have about 70 pounds of Lace Rock, which I have been told by my LFS should work fine if I add another 30-40 pounds of live rock (provide a good foundation and the live rock for decent biofiltration...) That being said what is the difference between cured rock and uncured rock and because I want to do a reef, does live rock serve any other purpose than bio filtration... as if to say would the bio balls act the same way in the sump...? and how will my corals act with lace rock presence... should I ditch the lace rock and go all live rock?

I am using a crushed coral substrate (aragonite)
and have 2 CF 65 watt bulbs. but planning on adding 2 or 3 T5s
I have lots of water movement, 2 hydor 4's and 2 maxi jets which also do about 5-600 gph combined. for a total of maybe 3000 gph... too much??

I have a freshwater right now but saltwater is in my future
I am reading lots and lots and am buying up equipment slowly cause I want to do this right with the right stuff. expected start date of project will be as early as next spring. so I have lots of time to plan and read. please help in any way... I am open to ideas and products... but budget is always a concern

[Reefersutherland]

bueller.... bueller...