I was on subs but not for a rapid taper so I cant comment on any of that. I do know that if your dose was recorded that around here you would get 8-16mg a day. Around here is also East Coast USA so thats completely different then you.
You would most likely need 2-4mg of sub to hold you. Will it be enough to actually make it comfortably through the day is personal to you. I was injecting at least half a bundle a day to avoid being sick (I hate when they ask what was the most you would do, infinity if i could the most i would do in a day is infinity so its best to state the least needed to avoid being sick) Anyway, I probably could have gotten away with 4mg a day but I choose to be on 8mg to know it would block any opiate fully. I did this for personal reasons and I stock piled the other 8mg a day for emergency. Its best to start low because it is easier to come off if your not at a high dose but you may need to start higher then you thought.
The whole thing about recovery, programs, etc is the only way they will be successful is is you take control. Sure at first you may need someone to do it for you but eventually you will need to take control, it will most likely happen organically in that you will start to feel like you dont need it getting medicated every day is a hassle and you want to get off fully. That is the turning point where you are ready to taper. Mind you that is for me and that is how my recovery goes eventually i get fed up and feel like choosing to take the methadone from them is becoming more hassle then its worth and I get off.
I dont know about rapid tapers. I think only a select few people can do them and return to their lives immediately after. Its not because they dont work but you need to learn defenses against using and that comes with time. Good luck though!