I am a newbie with PySide. I have a QGridlayout with QLabel's and I want to add/remove/update QLabel. 

Is it possible to create QList of QLabel with PySide similar to Qt in C++? After I populate the QGridlayout with QLabel and I want to dynamically increase/decrease the number of items in QGridlayout.
Is QListWidget/QListWidgetItem only way to create list in PySide? Can it be used with QLabel/QPixmap?
Sure. The python code will look just like C++ would look, sans syntax adaptations.
No. You can use a QStandardItemModel, or a custom model. In addition, there's no point to creating QLabel delegates for model data, since all standard views handle images and pixmaps available from Qt::DecorationRole. If all you want is a list of images, even a custom model would be trivial.
List of QLabel in PySide/Qt