Where should a project be created? (own directory because of the thumbs/ladspa/proxy directories that will be created, and because it just works™)
What are the thumbs/ladspa/... directories good for? Can they be deleted? (→ Yes, just don't delete the titles directory if some .kdenlivetitle files were saved in there. Deleting the thumbs directory can sometimes be the solution to crashes when loading a project.)
Project profile vs. Render profile: What is the difference, how to chose correctly?