Hi, Laszlo!
Thanks for the question & feedback!
1. To connect 2 notes between 2 bars use "Extended" marker. Attach it to the first note (select note, press "Add Marker", select "Extended"). Then in the game, you need to add game logic to cover this scenario/connect them (check presence of the "Extended" marker in "markers" field)
Just an example of handling extended notes in the game https://github.com/v-pukman-gd/music-tiles/blob/e2d065b48bf2bf60523e63cabbf119a5...
2. The is no copy-paste feature yet. It is in my queue and I'm planning to add it soon
Vic