Hey Beeguiles!
I went through and read every post here about the wrasses and your issues! I'm so sorry to see that you have had some many problems and it's awesome to see that you are keeping at it! I have a couple suggestions that might help with a couple of your issues though.
I have had 2 Wrasses in my tank for about 7months and over the last 2 weeks I added 2 more. I started with a Yellow Coris Wrasse, then picked up a Leopard Wrasse, and over the last two weeks I added a Tonozu Wrasse and a Lubbocks Wrasse.
I'm on my second Yellow Coris Wrasse because the first one I brought home I didn't know he was missing his lower jaw and he died a few hours after I brought him home, but the new one is eating and doing wonderful really haven't had any issues with him. The Leopard Wrasse was a fish that I new I had to have when I saw him, they are just way to awesome looking. I'm totally new to this hobby so I figured I would read up on him, cause I've noticed the more colorful a fish is the harder they seem to be to keep, and I found out what you did, they don't travel well, and my lfs guy told me this and he only had it in for a few days. So I watched it for about 2 months before I finally bought it. Whenever I went in to get water my lfs would feed it and I watched it for a while and since I had already paid for it he wasn't going to sell it. But he said to me that it's good to keep them in the store for at least a month to make sure they are eating and adjusting well.
The Tonozu Wrasse is such a sweet looking fish. I highly recommend looking into one if you can. Such pretty colors when he flashes his fins. I am on my second Lubbock's Wrasse, but the loss of the first one was completely my fault. He did get chased around some, but I didn't acclimate him long enough and my PH was way too low. The second one just as the first was chased around by my Coral Beauty Angel, but other than that he seemed ok when I put him in last night, so hopefully he will come out ok.
One word of caution my lfs guy gave me was not to put too many wrasses of similar shape or size in the same tank together, cause they will take each other out. So that may be your issue...So unless you are getting a mated pair you may want to just stick to one type of Leopard.
One thing I've noticed with mine though they are all different shapes and colors in some way. The leopard has his pattern, the yellow is well yellow, the tonozu is bright red with yellow flashing fins, they I have had no problems with, nothing chased the tonozu when I put him in and he gets along with everyone great. But the Lubbock's kinda has the same color scheme as my coral beauty so that might be why he is getting chased around.
As for your phosphate issue, I have this awesome stuff that for the life of me I can't remember the name of right now, but I will check it out and let you know later tonight..It's just in a reactor and it lasts 3 months and when It's running I don't have any phosphate issues at all. It's fairly cheap too.
Whew that was a long posts. Hopefully some of the info can help you out some and best of luck!