Finally figured out how it works. Here you go!
The reason why people believe that levels are most important when determining your accuracy versus a mob is because... well... it is. If you are one level below the enemy, you will always miss 5% of the time regardless of what you do. Since Mob's avoid has been drastically reduced (Jr. Kitties only have 8 avoid!), your total ACC means less than your total level.
To hit an enemy 100% of the time, both of the following conditions must be met:
1. Your ACC must be equal to or greater than the mob's avoid.
2. Your level must be equal to or greater than the mob's level.
For example, because Pink Bean has 625 avoid, you need 625 ACC and be at the same level to hit him 100% of the time. Very simple!
But let's say you don't have 625 ACC and you only have 150 instead. You are, though, at the same level as Pink Bean. What will your ACC rate be?
AccuracyRate = sqrt(150) - sqrt(625) + 100
AccuracyRate = 12 - 25 + 100
You'd miss only 13% of the time.
I would strongly encourage KMS(T) people to test this formula out. Thanks!