But if the deity is perfect, the flaws inherent in his creations must be by design. And of they are by design, he must have a perfect grasp of our reactions to the universe, so none of us are ultimately responsible for those actions.

Now, if he doesn't have a perfect grasp of our actions, or of the universe which shapes those actions, then we are ultimately responsible for our actions and none of them are by design, for he is imperfect.

It's the oldest question in the book - if an all-powerful deity can destroy evil but does not, it is itself evil. If the deity detests evil but cannot destroy it, it is not all-powerful.

Same thing with prayer. Unfortunate events in all parts of the world are accepted as part of a greater plan, but people constantly pray against unfortunate events. If there is a greater plan, then prayer is a pointless exercise - but if prayer can sway the deity in terms of fate, then there is no plan, and the fate of the world is not on a straight line, but on a web of prayer-based decisions made by the same deity, extending infinitely in all directions.