Lets deal with your points one-by-one.
1) The determined skeptic can always raise the issue that any argument assumes that logic does apply - and that therefore we can only be certain of the conclusion (i.e. that logic does apply) if it is in fact the case that logic DOES apply. There is a clear circularity.
2) You are not understanding the point correctly. Unless your dea of "imposing" logic means only that it is "imposed" on entities with knowledge then my argument does not single out entities with knowledge at all.
My point is that
a) any explanation must assume that logic does apply to ALL entities involved in the explanation.
b) for logic to be (meaningfully) imposed on an entity it must be the case that logic does not apply to that entity prior to that imposition.
c) the explanation must deal with the imposition - and therefore with the entity as it is prior to the imposition, when logic does not apply to it. This contradicts a) and therefore no such explanation is possible.
3) Again you are in error. My suggestion was that by assuming that the universe was created ex nihilo with the applicability of logic guaranteed from the start it is possible to avoid the problem. Since there is no prior state at all there is no prior state where logic does not apply. You are correct, however, that such an explanation still assumes that logic is applicable to God (see 2 a) above) and does not explain why.
4) You are not correct in your final point. It is not even nearly sufficient to show that necessity is not an adequate account - it must be shown that there is NO possible account which takes the truths of logic as necessary truths. It is also necessary to produce an account which relies on the existence of the Christian God and cannot work for any concievable deity other than the Christian God.