A number of those I bet never get to theaters. . . . Just a guess.
Okay: re: Sue Storms couture: it's only at the beginning she has to strip to be invisible, and she expresses momentary discomfort at the trend, all for laughs. Reed discovers that the uniforms they wore into space had also been affected by the cosmic radiation and were "unstable" so that Sue's would turn invisible with her, his would stretch infinitesmally, Johnny's wouldn't incinerate, and Ben's would withstand his galeforce farts.