Puritan Board Freshman
The reason God can't do these things is because we have not specified a thing to do; we have contradicted ourselves in the description. "A rock too heavy for the Almighty" is a self-contradiction, because the Almighty is...All Mighty! Therefore, by definition, such a rock can't exist. So your question boils down to: "Can God create something which cannot exist?" Of course not; that's a self-contradiction. God's "inability" to do such a thing does not indicate a lack in God; rather, it indicates our failure to define what it is we are asking.