The fact that you're excreting more bromide than average means (either of or both of) two things: you have bromide to excrete and your body is actually good at excreting it. First thing is not a good thing obviously, but in our society hardly avoidable. Second thing is a good thing.
The fact that you're excreting so much Iodine can also mean two things: either you're Iodine sufficient or your NIS don't work properly. When the NIS don't work, the Iodine doesn't get absorbed by the cells and just runs through you.
To get the NIS working: salt (you need sodium), potassium (you need sodium and potassium to be in balance), vitamin C, B2 and B3 + rest of the iodine protocol. See Brownstein on this.