Clearing things up, for starters I honestly never thought of the Roadrunner being a desert themed attraction in a seaport since the area already has a Roadrunner Express themed kiddie coaster. I guess I'm more open with expanding on the Seaport theme now. There's certainly some things to be done with the Seaport, specifically there's an empty footprint from an old water playground and there's an indoor playground that takes up a fairly substantial footprint that still gets used but never draws in more than a few kids at a time. There's also a random out of place carousel back there that doesn't fit at all with the Looney Tunes theme, haha.
As for Sharks and Walrus...Walrus can go, Sharks should stay. The Walrus exhibit is probably going to be defunct by the end of the season anyways as two of the three walruses they had there have died and it's not mentally healthy to leave one alone for an extended period of time. So unless the park inherits a new walrus in the next few months it'll have to go anyways.
Shark Experience however, is an ICON. Simply put, as a fanboy of the park, you CANNOT remove it
In all seriousness, it's been there since park opening and still remains by far the most popular of all the park's animal exhibits. Getting rid of it would not go over well even if it meant freeing up space for a showbuilding. The sea lion stadium is too disconnected from the ski stadium to really blend the two unless we took out the surrounding Ocean Discovery penguin and stingray exhibits and made the walk from Monsoon Falls to the park's DC area into a Radiator Springs Racers/Cars Land style national park with the roadrunner coaster running through it. The queue for Roadrunner can still be in the Walrus Experience, and the ride can start in the old ski stadium which literally hits right up against the back of Walrus, but maybe after the first third of the ride we go over the path to the DC area and into a larger canyon set piece excavated from the old Sea Lion stadium. I can tell you the sea lion show still draws a crowd though, but it's far from being as iconic as Shark Experience.