well being omnipotent he gets everything right the first time, the idea that he couldn't stop his words getting changed is weird...
The point is humankind is free to draw his destiny. I mean, you are shown what you are capable of, how you behave and react. The point is that it's not something that God is "not able to", it is something that God tests the humans about their intentions when there is no force over it.

..and the Quran itself is open to interpretation in fact it contains the same sort of inconsistancys and unusually harsh sentiments (for a loving god to make) as the old testament.
Probably considering the facts about how previous religions were partly corrupted and were re-written by humans to serve their earthly desires, the way of dictiation may feel harsh. But take human nature into account, if you draw a responsibility line, man generally performs and obeys it at lower degrees. So loosened and soft messages would totally fail, me thinks. What's more this is religion -a dogma. In Islam, the first thing you accept is the unity of Allah. You accept the power of a superior being at first step. Watching the other concepts of Islam taking this rule of thumb into account, will make it more easier to comprehend the rest about it.

Thanks for your manner approaching neutrally inquisitive towards Islam.