Proposition 6 is the proposition the argument rests on.
A perfect creator does not create flaws.
Once unpacked, we have the following propositions which you argue are inconsistent:
P1. God (a perfect being exists)
P2. The bible, whose text is disputed, exists.
Now, P1 and P2 are neither explicitly nor formally contradictory.
This means that you are arguing that they are implicitly contradictory. But what does this mean? To argue that the aforementioned set of propositions is implicitly contradictory is to argue that one or more of the terms violates a logically necessary truth, but this would entail some implicit premises exist which you would argue are logically necessary truths. Looking back at propositions 1-5 of your argument, we can formulate from these propositions, several that of necessity have to serve as implicit logically necessary truths for the argument to go through.
Amending the argument to include these implicit premises, the revised argument reads:
P1. God (a perfect being exists)
P2. God, being omnipotent could see to it that the bible was indisputable.
P3. God, being all-good, would want to see to it that the bible was indisputable.
P4. The bible, which is disputable, exists.
In the above, the inclusion of P2 and P3 are the two propositions that must be logically necessary in order for the argument to go through.
It is important to understand what it is you are claiming here. The claim is quite ambitious. The claim is: given that the bible is disputable, it is impossible for God to exist. Since this is the nature of the claim, all that must be done to rebut it is to show that it is possible that God and a disputable bible can coexist.
So what reasons do you give to think that P2 is a logically necessary truth? If humans, who are the recipients of the inspired message, are significantly free, it very well may be that any possible world God actualizes will have people in it that for whatever reason, simply do not agree with each other about what the accurate interpretation of the bible is.
What about P3? Why think that this is a logically necessary truth? As long as it is possible that allowing the bible to be disputed achieves some good to such a degree that this good would either be equal to or greater than the good that would be achieved if the bible were indisputable, then the argument fails. Here a greater good would be the preservation of the capacity for humans to make significantly free moral choices by not being coerced or forced to accept the bible as God's revelation to man. Here God allows people to draw their own conclusions about His revelation and allows them to either accept it or reject it.
To conclude, highlighting a point made by a respected contributor
FrumiousBandersnatch all I have to do is provide a reason why God would allow His message to be disputable that is logically possible. And there are several. Each one addressing a particular proposition that must be a logically necessary truth in order for the argument to obtain.