I just received my 5.5 CS, the screen is touch pad and it is built with a little bit of toughness, still plastic but not cheap. DJI has the 7" back in stock, but I found one on another site. If you are use to using a phone as your monitor the 5.5 will work great, but if you are like me and use 10" tablets or goggles you will think the 5.5 size is bit small. today is a rare day in So Cal (cloudy), so I will hold off on a full review. Just like others, my interest in the CS is the bright screen in daylight conditions and future use with a ground station command center (Hdmi out).
As far as a damage screen, I would put it in the same category as with any other smart phone out today, It will depend how bad the screen is cracked if it will still work. The repair part is something you would have to take up with DJI.