If I may, I’ll try to summarize your concern to ensure I’m understanding you correctly. Calvin’s explanation of the tension between God’s will and our human responsibility left you unsatisfied. He didn’t clearly distinguish our responsibility for our own sin from God’s sovereignty over every action.
I think that’s a fair criticism of the closing chapters of Book 1. At times, he does seem to stop just short of making God the author of evil.
For me, I gave Calvin the benefit of the doubt because I see this same unresolved tension in Scripture. When I read Scripture, I see God’s sovereign will juxtaposed with man’s responsibility for sin, and I wonder how God’s sovereignty doesn’t make Him the author of sin. So after reading those chapters, I mostly thought, “Oh, even Calvin doesn’t clearly explain this paradox.” I had hoped he would provide a satisfying way of looking at the issue. Alas.
I realize this comment doesn’t provide any additional closure (and I particularly wish that Calvin had focused a bit more on the pastoral implications of this tension). I just wanted to make sure you didn’t feel alone!