Really nice condensed ‘how to improvise’ lesson here with some brilliant tips, standard stuff plus a little of your own personal approach but not so much there’s any danger of turning your channel into a a school of Chris Haig impersonators. Working from easy to hard (maybe you could have started with pentatonic as the simplest but then as a squeezeboxer myself maybe more violinists are familiar with scales). I always think of the climbdown at the end of the penultimate line as being a brief excursion into the key of C major before the final cadence takes you back into the home key of E minor. The chords Em E♭7 Dm D♭7 C could be thought of as a I VI II V turnaround in C major as they are all substitutes for those chords, III ♭III II ♭II I in C.
