Many people need to use video editing for small casual things, like uploading short clip to Youtube. Videos may come from non-standard sources, like mobile phones, web cams or digital cameras. Those people do not really want to learn about video editing, they just want get something trivial done, like add a tittle or combine two short clips.
I suggest redesign to MLT profile management so that 1) Profile selection is automatic, 2) Project setting and Manage profiles are combined and 3) project profile setting are visible on tool bar.
1) Automatic profile selection.
Kdenlive could check video clips added to project and first create profile matching to imported video then try to match it against existing profiles. If match is found existing profile name and properties could be show to user. If no match is found, temporal custom profile could be instantly created for the project without user intervention.
Adding second clip with different properties would invoke notification. If user clicks the notification he gets to chose which imported video properties to use in his project. If user ignores the notification, profile chosen based on first imported clip is used (no nagging).
2) Combining Project settings and MLT profile management.
Move Profile management to project profile selection. I see no reason to have them separate and located to different places. Then while choosing profile for a project, appropriate profile could be instantly created if no existing profile fits. There could also be possibility to save automatically created profile.
3) Project profile settings visible on user interface.
Fast profile selection from visible user interface (maybe from tool bar) would suit casual video editing needs. Unexperienced editor would not need to dig through menus, instead selection for automatic or manual profile would be visible. Selected profile properties would be visible next to selection for convenient confirmation.
Attached quick mock-up shows one possibility how this could be arranged. Mock-up shows automatic setting selected, flashing "!" notifying for possible need to change profile to match new imported file and menu opened for selection. Direct profile selection is grayed out, until manual profile selection is chosen.
I believe removing need to especially pay attention that profile is correct for the project would simplify video editing and increase usability for non-technical people.