I use the 0.8.1 version.
I had any problem.
1) "scale and tilt": the video rendered turn black.
2) "speed effect": when i type the number in box video's proportion changes.
3) "load old project": the effects on the timeline don't work.
I suggest any features.
1) In the title's panels add a button with "save and new as the same title".
2) When I add a title kdenlive ask me the name of this.
3) I suggest "change speed tool". For examples (if i have a clip with 90 frames but i need 132 frames,
i change clip's speed with this tool
4) Safe margin on preview's monitor.
5) When i record video show time of the video captured.
6) When i record video show options for set "video and audio", "only video" or "only audio"
7) Cross dissolve for titles
I hope that my contribute is ok.