1): This is probably an optimization, but randomly chunks just "pop-in" to have snow covering all of the blocks, suddenly, instead of one by one like in java (however, it still seems that when snow stacks itself onto previously coated blocks, it does do it one by one). Is this to create more evenly, flatly coated surfaces, because snow is able to stack, and randomization would create "biases" and therefore rough snow surfaces? 

2): Snow is sorted as if it is non-opaque. Snow obscures every pixel behind it, however, sometimes snow is found to have trouble with rendering behind or in front of water or other transparent blocks (like in the video I attached). It might be because it shares some rendering code in common with rain (which is semi-transparent, and therefore can have trouble sorting with other semi-transparent stuff), but snow shouldn't have any trouble as it is entirely opaque.

3): Sometimes it "rains" a bit inside a snowing chunk (and I know it's not supposed to be raining there at all because I can't use my riptide trident despite there being some raindrops), it's like the rain rendering bleeds into surrounding chunks, which are supposed to only be snowing inside.

4): When it snows, the leaf blocks become white, but sometimes this is glitchy, and only affects some blocks depending on maybe if some blocks are a few blocks higher up than others, then some of them might be white and some not. It might eventually realize its in a chunk where it's now snowing, and and therefore should render white.