I tested your project file today with my own media created with simpleScreenRecorder. I used same parameters as much as possible, but you did not indicate fps. I used 15. I did not reproduce the export crash. I used the export defaults, and it only took 1 hour 8 minutes to render on my 9 year old computer (very little screen activity).
Maybe there is a problem handing video files created by simpleScreenRecorder because I notice some strange things with frame rate reported by tools. In Shotcut, the file appears as 1000 fps. mediainfo shows:
Frame rate mode : Constant
Frame rate : 15.000 FPS
ffprobe, which is using the same libs as Shotcut, however, reports:
Stream #0:0: Video: h264 (High), yuv420p(tv, bt709, progressive), 1174x662 [SAR 1:1 DAR 587:331], 1k fps, 30 tbr, 1k tbn, 30 tbc (default)
I usually see 1000 fps with variable frame rate footage. Variable frame rate does not work good in Shotcut or any multitrack editor that I know of. Also, tbr, tbn, and tbc are also framerate-related fields; and they are showing some strange values. tbr typically matches fps, and frequently tbc is double fps.
There is very little in your project that can take advantage of parallel processing as there is no scaling, only a little fade filters, and that option does not affect encoding threading.
With Parallel processing turned off, my export test using defaults took 1 hour 23 minutes.