when adding a photo int he slideshow widget they get centered automatically and the only control option is fill vs no fill. is there a way to customize the image crop within the slideshow e.g. the top?
no not possible, but you could take your prefered layout software and create the slideshow images (having all the same dimensions) and arrange your images onto it. The portraitimages would have some white space then to the left and right. Then insert your slideshow images into the widget.