ffmpeg front end web script?
 

are there any simple off the shelf scripts that let you use ffmpeg from a webpage to create/trim clips, transcode, watermark etc?

Nope.

I could make one but no one wants to pay for anything.

There is no incentive to write code for people these days.
I can't make my labor cost back, there is too much theft.

hit me up, i have something for you.