Question

1. By a sculptor

Answer 1

Everything was right except number 4. Number 4 was ablative of agent. But thank you!

Answer 2

I'm doing my best to help. The answers would be:
1. By a sculptor - ablative of agent
2. by a patron - ablative of agent
3. By hammer and chisel - ablative of means (denotes the instrument)
4. by millions of people - ablative of means
5. by Bernini - ablative of agent
That's the best I could do. Hope the answers have come to your help.