Hi,
Sure, I can give some clarity.
In favor for gameplay challenge, we decided to make some changes to contracts. Each contract has an objective, bonus and deadline. This includes airlines as well and we think that this makes it a more interesting and challeningen gameplay. In the future, if your airport is popular you will be able to sign long term contracts (not implemented yet). Again we must always balance gameplay vs. realism and gameplay will always be the nr 1 choice here. Of course we are aware that this is not how it works in real life but then again we are not creating a airport simulator but an airport tycoon. 
As of now all stands/gates are available to all airlines. This will not change until the first release. Possibly later.
Right now each flight gets allocated 1 check-in desk, but as you can clearly see in the video, this is not working so well. So we will have to re-design and make sure that several check-in desks can be utilized for a single flight.
Thanks for your feedback.