KDE devs have been working on improving On-Screen Keyboard support in computers, mobile devices and TVs as part of the We Care About Your Input - KDE Goals initiative. Check out what has been done so far in Plasma Virtual Keyboard and tell them what you'd like to see next.
Camstasia is a "Screen Recording & Video Editing Software" while Kdenlive is a video editor that has an feature to record your screen. Your shortcomings with it are the lack of screenrecording featuresit seems, not a fair comparison. Although it still has some ground to cover before it becomes a great nle it is getting there with every release.
There is a big code refactoring going on and after that multicam is on the roadmap. There is also a project to rewrite the titler. I am sure any kind of input is most welcome. You can use the irc/telegram channels as well as mailing list to contact the team.
Well I work with professional video editing and it is my go to tool. I can relate and agree that yes it needs to improve in many aspects but all in all it attends my needs. After the refactoring version is released some cool pro features will be added like advanced trimming tools and nesting.
For now in the refactoring version you are able to copy-paste clips between open instances. Multiple timelines and nesting are on the roadmap but only after finishing the refactoring and then adding advanced trimming tools.
Although Kdenlive has had its fair share of crashes, maybe of them happen due to bad packaging, mostly by using wrong MLT version. Using the AppImage is a good solution.
