Hi,
I'n new this forum. This is my first topic. I need some support

How can I remove default K2 Category Item Images. (.catItemImageBlock & .itemImageBlock).
I've done this Admin >> Template Manager >> Developer ( <style> .catItemImageBlock { display: none; } .itemImageBlock { display: none; } </style> )

Is there any other way?

In demo K2 Listing menu, I see some images as category item. Where do they come from? How can I control them?

if i am correct, they are images from articles not categories.
When you edit the articles
components -> k2 -> items -> select article -> above the text box you will see an image tab