Well, brown stringy stuff is definitely just yeast. I guess the glass made the color look different, but there is always brown stringy stuff (yeast). Some of it will hang from the scoby, and some will fall to the bottom.
I hope it doesn't smell like pee!
Mine usually smells slightly of vinegar and also that "kombucha" smell that is hard to explain. I've heard people say it could taste like apple juice though.
How long has it been brewing? Basically there are 2 ways to tell if it's done. You can test the PH, and when it reaches 3, it's done. Or you can just keep tasting it until you like the way it tastes (not too sweet, fairly sour.)