1. How do the crisis suits get a 2+ cover save in terrain? Is there something I'm missing here?
If the crisis team has Shadowsun in the unit then she confers Stealth and Shrouded for a 4+ cover save in the open. Put the unit in some backfield ruins and utilize their 36 inch range while having a 2+ cover save then. Only things that will scare that unit are tau markerlights to strip cover followed by riptide pie plate or ap3 flamers in general. Other than that, the unit is pretty darn difficult to wound.
2. It was also noted that if you add marker drones to the commander his BS5 will 'buff' the drones? This only happens if he has a drone controller correct? They didn't mention the controller hence the reason I'm asking.
Correct you need drone controller to improve the drone ballistic skill. A unit that is putting a lot of eggs in one basket but does all-the-above:
Commander (iridium, stim injector, drone controller, C&C, Multispectrum, PEN chip)
4x crisis (2 missile pods, target lock)
That unit placed on a backfield objective in ruins cover will have a 2+ cover save, dish out 5 markerlights that another part of your army can use, and be able have the crisis suits shoot wherever you like using the benefits from the commander. If you have scary weapons shot at you then have the commander Look out Sir onto a marker drone and don't sweat. That said this is an expensive unit so if a stormsurge gets a couple markerlights onto this unit and lands a str10 ap2 pie plate....you will be very sad