If God is omnipotent, then God possesses the maximum amount of power possible. A being that is maximally powerful could thrust a knife through an innocent child's chest for amusement. After all, infitely powerful creatures can do this. But if God is also impeccable, then God essentially refrains from performing morally bad deeds. An impeccable being could never (because such a being would never?) thrust a knife through an innocent child's chest for amusement.
This seems to me to involve a very straightforward and obvious equivocation between different senses in which we say something 'can never' do something (cf. the scholastic distinction, especially as developed in the later scholastics, between God's absolute and ordinate power). Funkhouser does consider this in some sense; he calls it 'relativizing abilities to faculties', and odd phrase, given that faculties are abilities, and abilities are either faculties or specifications of faculties. In that sense, 'relativizing abilities to faculties' is the only thing anyone should ever do. Funkhouser does not recognize, however, that abilities can be 'relativized' to specifications of faculties, and so gives a sophistical argument for the claim that everything God wills is willed simpliciter. Naturally, since we can make no sense of God actually willing without willing something, this conclusion is absurd. So God can will some things (in virtue of the fact that it does not contradict the notion of divine will) but also might not be able to will those very same things (in virtue of the fact that it contradicts something else). On this line, omnipotence would be something predicated of divine will as such in virtue of the concept on its own, in distinction from (say) our concept of divine will + divine intellect. But it doesn't matter much whether one grants this; there are problems elsewhere in Funkhouser's argument.
There is, for instance, a problem with a premise he uses in his argument:
The Maximality of Omnipotence: If there is a possible being, B, that has the power to (i.e., can) bring about all the states of affairs that being A can bring about and then some, then being A is not omnipotent.
Now, it is clear that the state of affairs in question in matters of impeccability is God's sinning. It is entirely reasonable, however, to hold
(M) Nothing can make God sin.
This is entirely consistent with the Maximality of Omnipotence. Thus the whole problem is avoided. Funkhouser tries to get around this by making the state of affairs in question "morally bad states of affairs," but this simply won't do; for a state of affairs to be morally good or bad it has to be morally good or bad for someone. This 'someone' can only be God or a created person. If God, what I have said holds. If a created person, then we have to ask whether the following is consistent with impeccability:
(N) God can make a creature to sin.
And the answer is 'Yes, they are compatible' if God can make a creature sin without Himself sinning. Funkhouser, as far as I can see, provides no argument against this response.
He further goes on to argue that power is not intrinsically good; but all he shows is that it can be incidentally evil. The latter does not, however, conflict with the former, and indeed, traditionally, power presupposes good-qua-end, and therefore can never be wholly without good, but only (as it were) less with it. Power can be praiseworthy in a non-prudential sense, contrary to Funkhouser's claim; this is why we want good people to be as powerful as they are good, even apart from any benefit we receive from it: it is good for good people to be powerful. That we give moral properties a priority in praiseworthiness over power properties as to do not with any lack of intrinsic goodness on the part of power, but in the relation between the two kinds of intrinsic goodness.