If your cord is cool, you're cool
Maybe get a cable or chain to take up the weight of the lights. Even a string or rope would work but I like fireproof materials.
what is the thicknesss of the wires inside the flex ?
Hey, those "Y" expanders are not rated for that kind of use and I've personally seen them burn out before, being used like that. The one in the socket will go first..
You're using 150w.. why not just switch to a 150w HPS???
After looking at the chandelier hanging in my DR, yours isn't that bad. However, you risk losing all your bulbs if the fixture falls. If you're looking for ideas,
You can get something like this that for about 15 bucks. Same issue in a fall, but it will evenly distribute the light.