2, 3, 4 should not be done. There is no value in using any of those features. As mentioned, 5 is not a thing. That's spec politics, you shouldn't be doing any

2, 3, 4 should not be done. There is no value in using any of those features. As mentioned, 5 is not a thing. That's spec politics, you shouldn't be doing any of that. As for 1, well that's a whole other argument, and it's an opinion. You choose one, nobody cares what you choose.