How to import an image sequence into Blenders video editor with each image playing for one second? Is it possible to tell Blender somewhere, that each image should be playing for a certain amount of time or frames when importing them onto the timeline of the video sequence editor?
Yes you can!

Import the frames as a sequence of images like you normally would (which will make each image play for one frame). With the image sequence strip selected, click Strip > Separate Images (or tap the Y key), then you can set the frame length of each image in the sequence.