We towed our brand new BC 20X for 600 miles across PNW two days ago on just the tow ball; it was an out of state delivery, and I didn't get a chance to install the WD/Sway system yet. I had to buy a new tow ball mount because I miscalculated the numbers. If your TV sits low, you always need a rise (flip the mount so that the ball sits higher than the reciever). The rise length is the offset between the numbers you quoted. Refer - https://www.curtmfg.com/towing-acces...nts/learn-more
On Porsche Cayenne, I had to buy 4" rise. I originally bought 2" rise. Now I need to return it.
Regarding TV capacity, I believe you are referring to BC 16. IMHO, you are cutting a bit close on the tongue weight. Once you start loading the trailer, and add WD/Sway control, you would easily add 100-200 lbs or even more. That might put you at around 500 lbs range. You might want to rent one and tow around for few days to get an idea. I highly advice renting the exact unit once before buying it. You'll learn a LOT..