That stuff all looks like decent design you've got there, just make sure your plugging it into a solid made frame, (some things need a bit more stability built into it.) if the the above cross lats aren't secured, secure them with wire or zip ties, the more, the better, up to a point. I think you've got the right idea.
But I wouldn't put all the weight on something of Chinese design, I would spread it out, if possible. Even those little wire clips on that light can spread apart over time, and easily become disconnected. I've personally witnessed it happen. Keep the inside of that dog clean, and disassemble the light (if there are any fan intakes) and clean it out at minimum once yearly, (unplug before spraying cleaning) twice is better. If it's made of all passive heatsync, keep the tops clean, and dust free, even that powersupply, especially.
Keep air movement on it, and vent the hot air out the top if possible, and pulling, IMO, is better than pushing air. But others here might know better than I.