What kind of weather can these things endure and still keep the ground effect going?

Sea... Seaglider... seagulls ... oh.

This would be great in the Philippines, however there are a lot of fishermen in the open sea on tiny traditional dinghies which can pose a collision hazard.

A big part of the market for this kind of thing might be transport to offshore installations. Still lots of oil rigs out there new, probably soon to be lots of wind turbines that will need care and feeding.
If you're limited to one wing length above the waves and speeds under 200 mph, that probably means no flying in anything where wave heights are more than 1/4-1/3 of wing length. And probably wind speeds less than 30-40 kt. Otherwise there might be excessive, um, excursions in airspeed and altitude.

I wonder how a windy day with high waves would affect this thing. And what if higher waves are encountered midway during the flight?

This would be a great idea for long range search and rescue. We haven't had near peer war at sea since 1945 and have forgotten that we need more than helicopters to rescue pilots and ship sinking survivors near hostile landmasses and at extended ranges.

Nary a sign of any outriggers? Does it sit so solidly in the water, that a side gust won't tip those props for a swim?

That is so cool. But I always wonder what if the waves pick up significantly?

Regent is raising capital based on what? A drawing? A cartoon? A dream? Who do I make the check out to? Oh, wait, what are your sales? You don't even have a start date for the prototype? What are. you doing on SharkTank?

Great idea especially for an EV version. Just a bad design for flying in ground effect. First it needs a low wing so you can fly 8' higher on the same power or the same height on less power. If designed correctly the wings will raise the boat before the hydrofoil would take effect making it moot. The hull is too sharp/deep V and will dig into the water. A 30Deg deadrise would be much better. GEC chord is much more valuable than wingspan as you get lift from the trapped bubble of air under the wing. A long fore and aft wing length holds that bubble better.