Paul is talking to the critics of his teaching as though he were only talking to one person. You may need to use the plural here. (See: [[rc://en/ta/man/translate/figs-you]])
These rhetorical questions are complaints against God. You can translate them as strong statements. Alternate translation: "He should not find fault with us. No one has ever been able to withstand his will." (See: [[rc://en/ta/man/translate/figs-rquestion]])