To me at least the video and sound editing seem completely professional. You should consider hiring yourself out to other Cornish lang film makers, since some of the stuff is spoiled by awful editing (e.g. the sound on 'Homecoming' video). From a language POV it's not easy to make out the words, so two suggestions (maybe for a language orientated version) 1. add subtitles either in Cornish or English, 2. bring the vocals a bit further forward in the mix.

Mez dre vras, marthus da yw. Hemm yw a pyth rag avonsya an yeth, ha'n pow. Moy! moy! :-)