I've seen that before. Seems to be yeast that stuck to the sides on its way to the bottom. Some of it eventually settled to the bottom for me, some was still there when I bottled. Racked away from it no problem and the beer was great.
Agreed, totally normal. It's yeast getting caught on the sides of the carboy on it's way down. It'll settle out in time, and if it doesn't it's still not a concern.
Yeah that's fine, I sometimes gently rock the carboy to get this to fall to the bottom. Although in reality it would probably just stick to the sides when you transfer.