1)
Was David angry at Uriyah for not obeying?
1.
Malbim: Yes, but he did not show this. He suspected lest Uriyah knew what happened. He tried to probe this by speaking as if nothing is wrong.
2)
Why did he say "did you not come from the road"?
1.
Malbim: One is obligated to be intimate with his wife when he comes from the road. (Why do you not do so?)