An Irish Proverb I - Brandon Schwab Feedback Appreciated

A rough draft of something I wrote a while ago and never finished. As someone who has only professionally wrote for wind orchestras, and as someone who has never played a string instrument other than guitar, any and all criticism is welcome

Slurs should really only be used as markings for bowings on string instruments. Some traditionalists will tell you otherwise, but you run the risk of confusing modern players.
The z thing you're using as a tremolo marking is never seen. Three dashes should be used.
The intro with the mixolydian sounded fine, if not a bit rushed. The rest's reliance on Lydian mode/tritones sounded really off to me personally. Felt like a departure; fiddle music doesn't really use the tritone unless it's a leading tone.
 The way 118 is written is going to confuse a lot of people.
Overall it's a fine exercise, but it sounds mostly just like an exercise.