Looks good and sturdy. Have you considered adding a face frame around the cabinet and shelves to conceal your dado's? That will give your shelves a thicker look as well. Nicely done project!I did dado the dividers and the insides of the top/bottom/sides for the shelves and glued them all in place. Because this was my first project, and I didn't think too far ahead, the dado's run the length of the shelves/dividers, which are about 4" shorter than the total depth, so there are some unsightly exposed dado's on the backside. If I had planned better, I would have routed just enough for the shelves/dividers and used a chisel to square the ends of the grooves.
In theory, yes; however, you would have to really crank down on the U-bolts to make sure they're secure. Or, you could add in some sort of safety on the top of the conduit that hooks into the opening in case the U-bolts fail. Just make sure you test the weight limit before you mount the TV so if there is any failure, you wont ruin your screen.