I can appreciate why WIG is designed to fly low and take advantage of ground effect, but why would its ceiling be limited to 300ft? Is the wing section and loading totally inappropriate to wing-borne flight?
Seems to me that voluntarily cruising down there in CFIT country you are just asking for a hiccup, autopilot, rad alt and/or systems failure and you're into the drink (or swamps, marshes etc). You'd also need ahead radar cover for IMC protection against flying into the sides of ships, masts, guy-wires, ice-floes etc. In addition it would need an autozoom-up capability for any steepish turns.
Seems to be little tactical or strategic stealth adavantage as an AWACS is going to paint it OK at 100 nms.... and it would be an easy kill for any fighter....
Seems to me (also) that it would be spending a lot of time down there in the high threat-hazard area.... and with limited LOS comms abilities. Troops might be better off than in an Osprey though