There is nothing wrong with providing 5V on the 5V pin, as long as you do not attach USB or external power to Vin. In which case, you'll have two sources providing 5V on the 5V node.
I'm not sure what you mean by "the 10V Input". What 10V input?
There is nothing wrong with providing 5V on the 5V pin, as long as you do not attach USB or external power to Vin. In which case, you'll have two sources providing 5V on the 5V node.
I'm not sure what you mean by "the 10V Input". What 10V input?