Sorry cannot help you, but that door opening is typical cessna I think. On most c152's the doors have a gap of about 1cm, wonder why that is. I've had the door opening in flight several times. Especially on take off it can be disturbing when the door opens. The door lock does get worn if you just slam the door closed on ground; I made myself the habit of pulling the door handle out, then close the door and close the door handle again and give it a good punch before take off to check if it stays closed.
Conserning the ailerons, I also found that all c152 were feeling different from other c152's. On some you could get more than 180° wheel travel while ailerons only followed in the 180° range, on others you turned the wheel, but the first 5° the ailerons didn't move at all. It depends on wear and age I guess. Nothing really bad.