I havent tried it recently but it used to be very unstable (crashing all the time). Kdenlive is the only editor on Linux which is stable enough to work with.

Whats amazing is that a few years ago the biggest complaint about Kdenlive was that it was that it was terribly unstable.

They've done a fantastic job of fixing that.

Both Shotcut and Kdenlive use the MLT framework under the hood. I used both for a few weeks now and they seem equally stable for small projects.

Tried, no option to change aspect ratio of the video.

That's one of those weird quirks with Shotcut -- it takes the aspect ratio / resolution settings from the first video/clip you import into the app.