Looking at that pic of the Jeopardy! set, I must say I like it a lot more with the pillared backdrop. It adds a "collegiate" presence IMO.
Taping out of in L.A. does and doesn't surprise me. I know Sony's base is in Culver City, and that Wheel/Jeopardy! tape there, but it still surprises me given Dan's being on the East Coast.
That being said, it makes sense if the Sports Jeopardy! crew members come from the mothership (esp. if the shows tape on the same lot), as opposed to having to get a new crew ready in NYC or CT, or worse, paying for everyone to travel cross-country, esp. if there's already other tournaments. Paying for a host to commute is a much better option than paying for dozens of production staff.