Got some questions:
What time are the rules seminars you must attend at GKTW?
We have an opportunity to stay an extra night, but have to leave GKTW and check in elsewhere. Is it worth the extra effort for another day? I was thinking a fun day at the beach or space center or something might be nice. We get four day park tickets, two day US/IOF and one day sea world, correct?
It's THREE park hopper Disney passes, 2 days US/IOF and one Sea World.
The orientation times vary. We had this issue when we went and here is what they told me: The orientation times are 9:00 AM, 3:30 (ish), and 7:45...BUT...they cancel the one at 9:00 am if there are no families checking in late that need the 9:00 am orientation. And they don't always have the one mid-afternoon either. But the one in the evening is a sure bet each day.
You can call in the evening the day before and they can tell you the orientation times. You can't really "do" anything in the parks until after the orientation.
I would definitely do an extra day! Even two or three...since they are paying for your transportation...you could have a "down" day and not feel like you are wasting your "time"...If we could do it again...we would have added 3 days. We would have done one travel day...3 days in the parks...one down day...3 more days at the parks...and then the travel day.

You basically get 6 full days of park passes...so that would be a good schedule. But you will have to pay for the room and food, etc for the extra days. Our days would have been easily covered by our MAW expense check, though. ?? But each state is different about that.
Another question do you get to take advantage of Extra Magic Hours with the tickets supplied by MAW?
You don't get to take advantage of the EMH...BUT...I have to say, that honestly, you really don't want to. All of my research has indicated that the parks that have EMH are VERY, VERY busy...so I would literally AVOID the parks that have EMH.
What dates are you going to be in the parks? I will look at the crowd calendar that I have paid for on the internet and make some suggestion as to which parks may be good on the days? This worked VERY well for us - well, for the three days we actually were at the parks! (Since we got sick.

) PM me if you are interested!
And anyone else reading this... you can PM me your dates if you are interested in this...the basic strategy is to avoid the parks with EMH, since many people don't have the park hopper option and have to stay at one park all day. But it is a "logic" problem...and I LOVE logic problems! I will be glad to help you plan this aspect.