I would like to be able to move around using vim shortcuts hjkl instead of the arrow keys. Would be great to be able to customize the shortcuts.

Dotgrid is open source! You could make a fork with shortcuts that you think would feel more natural :)

https://github.com/hundredrabbits/Dotgrid/blob/master/desktop/sources/scripts/cl...

Thanks for the link to where it's set, will fix!