Ok I'm going to play devils advocate and re-ask the question in my original post. "What am I waiting for", surely the rock and the corals are the only things that can change the water to any degree and they are established so what's going to change?
I have kept tropicals for over 2 years with no changes in water params at all. I have kept the nano, which cycled very slightly and has been at 0 Phos and <5 Nitrates for 3 months. My Reef is at 0 Phos and Nitrates and maintaining pH 8.3, 420 Calcium and .5 temp fluctuation this doesn't seem to be changing and I'm not having any signs that it will. I quarantine everything and have never lost a fish to disease (although I have successfully treated Brooklynella, Ich and Fin rot which were got rid of in the quarantine tank). I run very simple set ups and most of the major crashes I read about are down to someone mucking about with a dosing pump or a reactor. So if a year down the line I am still having no problems and still doing water changes as normal and still maintaining my levels what have I learn't? Is the consensus that I'm not going to get experience of dealing with problems unless something goes wrong or I make a mistake?
Please understand I'm not trying to be awkward and I know people can be stupid, god knows most of the world is stupid. On the malawi forums they tell you, you can't mix Haps and Mbuna, but you can and to no detriment of the Haps. Apparently you also can't raise fry by letting them spit in the tank and survive on what they can grab at feeding time without getting eaten, and they must be fed a special diet, but I made over £150 in the last year from fish that did just that.
Wouldn't it be fairest to put the Nem in a less full tank and let him take his pick of the spot he wants and then add other stuff once he has settled? I have heard of people who insist of moving a nem when it settles because it isn't where they want it, and then moan because it's killing everything, now that's stupid!