Hacking into cpei300

I have few questions for network savvy people here:

I have Motorola CPEi300 in door device (You know that thermos like device):

(1) When I check the status of my network at the status page of the CPE, I am given an IP which starts with 10.x.y.z. Does that mean I am not given a live IP, rather I am going through some proxy?

(2) When I do trace route to anything, my first 3 hops are all have IP starting with 10.x.y.z before I hit a machine which has 58.something IP. Why is it like that? Why don't my cpe has an IP starting with 58.somthing ?

(3) I want to play with few settings of CPE like e.g. changing the default gateway but I can't find any option to change it. Can you tell me how I can do that? Or did Wateen copied it in the firmware and I would need to replace the firmware?

Thanks in advance.