FiNeRaIn Yawn- its to be expected.
The sooner people start standing up for themselves the better- tell the stewards to get lost if you think you are being treated unfairly
If you tell a steward to get lost, they will probably throw you out of the stadium for public disorder or something. If you think a steward is being unfair to you then engage in a normal conversation with them, asking them on what grounds is their action justified. If they continue to be unfair to you then take down their details (look for a name badge or number) and mention that you will be taking the matter up with the stadium management. Now, you're turning the tables and singling out this particular steward. They can't throw you out as you haven't behaved in a disorderly manner. If they do throw you out then pop into the club reception and make a formal complaint.
As for people standing, this is a much often discussed subject in any football stadium. The club is required by the terms of their public licence to make sure everyone is seated (H&S etc) - not only this, but people who remain standing are actually obscuring the view of those seated behind. The ideal solution would be for clubs to reintroduce terraces in some parts of the stadium but this is probably never going to happen.