Ok started playing with Heartseeker again. I made a few changes to your classes.
I changed the Barbarian to use it's Rage ability up to level times per day. (Might scale that back to 1/2 level round up. Seeing how it works out in play).
For the Bard changed a few songs (Song of Rest: Party members heal 1d3 extra HP during long rest./ Song of Vicious Mockery: Gives up to 1d4 creatures disadvantage on next attack or save./ Song of Inspiration: Give up to 1d4 creatures advantage on next attack or save.) and gave them a Rapier Wit ability (Target must be able to hear and understand the bard, 20' range, save vs Aura or take 1d4+1 damage, Usable level times a day).
I think a lot depends on how often the PCs get to rest and how long a day passes. Usually the PCs have more then a single combat encounter when on an adventure so trying to give them a little more ability.