I was wondering if the following would be possible.

Lets say I have created an edit and placed several clips in the timeline with all sorts of cuts, transitions and effects.
Now I recognized, that some of the clips do indeed need stabilizing. If I do this I end up with a new clip.

Is there an easy way to replace the clip in the timeline without having to redo all the effects, cuts, transitions etc.

What I do currently is to manually adjust all these parameters, but that is very tiresome, especially if you have 100+ clips to process.

The stabilizing was just an example. This also is an issue if I process the source clips outside kdenlive and want to use the processed file instead of the original one. I could just rename the new one to the old ones name, but that is tedious as well.

Is there any better way ?

You could try opening the project file in a text or xml editor. And then you could do a search and replace and replace your old clip name with your new stabilised clip name.

Do this on a copy of your project file of course.

Thank you for the idea. It works in a way. But just changing the filename does not work well if you want to do further things with the clip e.g. create/recreate the proxy. There seems to be some information missing.

This also makes the whole project a bit unstable and I'd rather do it by hand then compromise my work of countless hours :)

Recreating proxies is no issue: simply open the project properties, change tabs until you find the one containing a button to delete proxies. Your proxies will then be recreated automatically after you close the project properties.