Is it possible to merge two ffmpeg commands into one?
Can't test the below now, but it should be

ffmpeg -itsoffset 2 -i original.mp4 -i watermark.png -loop 1 -t 2.5 -i intro.png -filter_complex "[2:v] fade=out:50:10:alpha=1 [intro]; [0][1]overlay=W-w-45:H-h-35[main];[main][intro] overlay=eof_action=pass [v]" -map "[v]" -map 0:a output.mp4