In theory, yes. Since driving one 60hz 4k display at 4:4:4 chroma takes roughly 18gbps then daisy chaining 2 displays should be possible.

It just means on the spec sheet its enough bandwidth for 2 4k streams. (HDMI 1.4 4k@60FPS == ~18Gbps)

Yeah. One 4k60 screen is between five and six gbps.

Yes, or with a hub.