Horse with secondary laminitis

Cheryl Hooper <cherylhooper1@...>

(reposting from ECIR)
Hi.  I'm after some advice for my horse with laminitis.   
4 months ago he suffered a penetrating injury to his off hind resulting in infection of his coffin joint and surrounding structures.  This was treated with systemic antibiotics, local antibiotics injected into the distal veins whilst a tourniquet was applied, flushing of the joint with saline, intraarticular antibiotics and pain relief.  He was given a poor prognosis for ever being sound again.  At the time my vet and my farrier in collaboration placed a heal-raising shoe on his other hind foot to prevent secondary laminitis.   This was unsuccessful, and as the originally injured hind foot healed, he became shifting leg lame, and eventually obviously rather lame on his near hind.   He was xrayed and both the vet and the farrier diagnosed "catastrophic pedal bone rotation and sinking with 1mm of sole remaining between the tip of the pedal bone and the ground".  For the second time in 2 months I was advised to euthanize my horse.   
Both the Vet and farrier in collaboration have placed both his hind feet in raised heel shoes and we are monitoring his progress with 7-10day xrays.    It is coming up 10 weeks since diagnosis (of laminitis) and we have radiographic evidence of the sole detaching.  Which we are monitoring.  I was told at last weeks xrays we had 4mm of sole growth at the tip of the pedal bone but when I look at the xray I struggle to see any difference.   The more I read the more want to pull these shoes off and fire the farrier.   
My question(s) are: 
(1).  I dont want to just pull these shoes off and whack off his heals.  How 'quickly' would you advise I do this process?  
(2) Assuming I can get blood supply back to beneath the coffin bone, over what sort of time frame would we be looking , on average, (realizing that it's all individual), that i could start to see sole growth?  I.e. at what point do we say 'well this isnt working either'.  Given hes had no blood supply for 10+ weeks now.  
(3) can you offer any polite ways of saying to my farrier hes fired? I cant fire my vet because I still need follow up xrays and there is no other equine vet in the area.  I need to stay on his good side despite firing his accomplice.