So... how bout a sliding scale between 1-100% for normal raids.
You set it at 1, all boss stats are reduced by 50%(whatever number) and the gear that drop stats are reduced to a standardized point(110% of heroic 5 man or the previous tier) as you crank up the number both slide in stats accordingly.
Set to 10 - you get 45% recuded stats - gear stats go up 10% of the differnce between 110% of previous tier and full teir level.
20 gets 40% stats and 20% towards tier level gear drop stats
30 gets 35% stats and 30% towards.....
1-25(2 mech removed),26-75=easy mode(1 mech removed),76-99= normal(full mech but tuned away from hard DPS/Heal/tank "checks") - 100= Heroic full mech + strict checks + extra mech
Remove all these arbitrary "easy" normal" hard - just make it a number.