These were problems to solve with the camera even before it went in the water. If you are using the camera for HDMI the orientation is locked. You need a GoPro Labs firmware mod to rotate it 180 degrees if the camera mount is to be used on the top of the camera.
Ah ok, i misunderstood, your problem is the image upside down, not a problem for a video as i can be flipped software side but not feasible in your case where the signal goes directly to any screen.
What about a L bracket on your stick and install the GoPro the correct way on the L-Bracket?
Just a hint from a very seasoned underwater photographer: Fill the housing with kitchen paper and then immerse it, the humid part of the paper will show where the water enters.
Look if you can find and install a watertight cable gland, a overkill for the low depth as they are in use also for 200 ft, or buy the housing who has it already you linked. It will take care of the leaks, but not of the overheating problem.
A scratched o-ring groove is also frequently the source for flooding a camera, pull the o-ring pinching it till a part pops out and don't use and hard pinted device to lift it out, in extreme a toothpick. Clean the groove with a lintless paper (f.e. for camera optics), rub a very small amount of silicone grease berween your fingers and slide the o.ting thru them, the o-ring must be slightly shiny abut absolutely without any visible traces of silicone grease. Use only silicone grease as other grease may lead that o-ring swells and will leak.
The above hints kept my 10K underwater cameras safe and dry during about 2500 dives down to 250ft.
I wonder if you can find what the "Shark show" production companies use to film underwater. Maybe there is something on the black market that wont cost $$$ to purchase?
There are several aluminum underwater housings for the GoPro and GoPro's are widely used in budget underwater film production. However those housings are very expensive and i am not sure / believe that they don't solve the problem that camera overheat after more than a certain time recording. The only way i could use a GoPro and cheap copies was to film a sequence and switch the camera off, if i left the camera on she over heated.
Chris