I have a script for FFmpeg however I would like to add functions to it :

ffmpeg -y -i input.mp4 -i filter.png -af "[0:a]atempo=1.15,volume=1.6,pan=stereo|c0<c0+0*c1|c1<c0+0*c1,aeval=val(0)|-val(1)" -filter_complex "[0:v]setpts=PTS/1.15,crop=iw/1.2:ih/1.2,boxblur=1:2,scale=1280:720 [v1]; [v1][1:v]overlay=0:0,setdar=16/9" -vcodec libx264 -pix_fmt yuv420p -r 30 -g 60 -b:v 1400k -profile:v main -level 3.1 -acodec libmp3lame -b:a 128k -ar 44100 -metadata title="" -metadata artist="" -metadata album_artist="" -metadata album="" -metadata date="" -metadata track="" -metadata genre="" -metadata publisher="" -metadata encoded_by="" -metadata copyright="" -metadata composer="" -metadata performer="" -metadata TIT1="" -metadata TIT3="" -metadata disc="" -metadata TKEY="" -metadata TBPM="" -metadata language="eng" -metadata encoder="" -threads 0 -preset superfast output.mp4
How to add these functions in the script :

Cut 5s from start of videos
Cut videos into 30s parts
Flip video image horizontally
Remove audio stream from videos
Add music to videos
Apply all these functions to multiple videos

Thank you for your help