No but really my girlfriend and I are going to SeaWorld because she's never been and I haven't been in so long I can't really remember going!

We're Disney people to the core and we realize that SW will be different...but just how much different will it be? So heres some of my main concerns with SW! Thanks in advance for the help!
1) Does SW allow bags inside for us to carry our wallets and drinks and stuff? We usually wear gym clothes basically so it will be comfortable for us!

But even when we dress normally we still like to carry a bag so we don't have to waste money on snacks and drinks and have a place to keep our purchases safe!
Yes, you can take bags in! Just no straws or plastic lids or ballons; just like DAK...for the safety of the animals!
2) If they do allow bags when youre on a ride like Kraken and Manta do they have cubbies that you can put your bags in like some parks do or are you basically responsible for finding your own way to keep the bag safe?
No, you're not allowed to bring bags in. SW is probably the worst park about bags and rides. There are lockers that I think are .50 or .75 to rent at all of the ride entrances. The employees at the beginning of the lines will tell you have to leave it with a non rider, or rent a locker.
3) Is SW a all day park? We don't want to miss anything at all. We want to see all the shows ride all the rides and even see the fireworks if they're still doing them September 27th-Oct 1st. (not sure which day we're going there) If we wanted to do it all would we have to be at the gates at opening?
Everyone's opinions will differ, but I think it's an all day park. There are 4 big rides (Manta, Kraken, Journey to Atlantis, and WIld Arctic), 3 main shows that will take an hour each to see (half hour before the show to get good seats, half hour to watch the show) as well as several animal exhibits to see.There are also backstage tours and special animal tours to get more up close with the animals.
4) Are there anythings that couples have fun doing there? Like say eating at the restaurant with the sharks swimming around you? Is that hard to get into? Should I make a reservation? I always like to surprise her like last time we ate at Crystal Palace in the Magic Kingdom. Is there anywhere like that at SW?
Sounds like you've already done your research...Sharks Underwater Grill is currently the only sit down resturant open. They will be opening Dine With Shamu at somepoint, but it's still unknown as to when. If you want to eat at Sharks, then yes, book a reservation! If you want to do something extra special, I suggest looking into some of the animal tours they offer. There is a behind the scens where you get to see the back stage animal rescue areas, pet a shark, pet a penguin, and see the back stage of some of wild arctic I believe. You can also pay to have a private interaction with Beluga Whales, or take a tour to see Penguins/Puffins; or a Dolphin tour.
Again guys thanks for the help! If you have any general tips please also include them! We want to love SW just like we love Disney!