For your Lord's Day reflection.
>> Many monergists, however, would counter that when the heart has been regenerated, man accepts God’s call freely and so would defend that their Christianity, while not predicated on freedom, did, in fact, involve their freedom. << — From Wikipedia
I hadn’t known this position to be consistent with Calvinism, but it certainly is consistent with Catholicism. (There are other statements, however, which suggest utter depravity, which is not compatible with Catholicism.**) Certainly, nothing you posted up through Martin Luther contradicts this understanding.
>> Opponents would argue that this type of freedom is akin to being free to take the one-and-only choice available. <<
Such opponents, I would say, misunderstand freedom. Freedom is NOT the ability to act capriciously. In fact, the person who acts capriciously is not acting based on any internal principle, and, therefore, in a sense, cannot be acting freely, merely chaotically. Freedom is the ability to act according to one’s own principles. If one’s principles are to act in a godly manner, than one is most free when he acts in a godly manner. So, Paul’s apparently contradictory notions of being a slave to Christ, while being liberated in Christ make sense: he is free to do what he desires to do, because what he desires to do is to be part of the body of Christ. When he could act capriciously in ignorance, he was not free, because he could not do what he ought.