Hey Robb, sorry to hear about your troubles.  I haven't read this build thread until just now.  Imo, most of your troubles are because of the dry rock.  It takes a long time for dry rock to populate like live rock, and the less live rock (more dead rock) the longer it takes.  If you go 50/50 live and dead it will take about a year for the rock to really be considered live imo.  I think you're looking at quite a long time.  No algae is a bad sign.  If you can't grow coralline, you probably can't grow corals.
If I were you I wouldn't waste any more money on water changes.  If there is no significant uptake of calcium, alkalinity, and magnesium, and no nitrate build up I would cut back water changes to no more than 10% per 2 weeks.  There is no point in doing them.  I would take the money you save doing that, and go buy 100 lbs of good quality live rock off the classifieds on here for $4/lb.  Just make sure there are no aiptasia or bubble algae, or other nasty stuff.  Stuff that all in the tank for at least 6 months, and then after that you can start removing some pieces to go back to the look you're going for.
JMHO.  Hope it helps.  
