Since I have been thinking of collecting some high bay fixtures for the sole purpose of running certain HID lamps in a base up configuration, I am wondering if there are any ways to safely hang a HID high bay fixture to the ceiling by using a swag lamp kit or are there any heavy duty chains and swag hooks that can help support the weight of HID high bay fixtures without having to remotely ballast them? I personally enjoy the look of HID high bay fixtures whenever they are oriented properly with the lampholder mounted base up. I would like to make sure that the fixtures do not fall from the ceiling or cause any damage.

In your home, I wouldn't recommend you to use a long chain, because the ceiling is much lower than in a factory, GYM, etc. Your highbay would be to close to the floor.
The gear compartment should be ceiling mounted, and I don't think it is possible to do this with a long chain.

This could be done in similar fashion to a plant grow light, where the ballast is remotely connected and sits on the floor. Then the luminaire is lightweight and mounting is basically like an incandescent light. But with full-wattage HID, it may be too bright at such a low mounting height and look very disproportional in the room.

Mounting a high bay as-is with the ballast still in it would mean using heavy chains, hooks and bolts and making sure it’s fastened well into a ceiling stud. You’ll have big holes to fill when removing it later. Another thing to be concerned about is lamp heat if mounting close to the ceiling.

Yeah I'd remote mount the ballast in a suitable enclosure (you could even source a 400w MH grow light ballast and wire the socket on the highbay it) or I suppose a low wattage MH ballast such a 50w, 70w or 100w MH would give a similar effect but with a more reasonable lumen output for use in a residence.

For mounting if you're able to install a properly weight rated junction box at your location you could go with stem mounting, which would look the cleanest.