Though it really doesn't matter what Barnabas was like as a child because the point here is that the life-force source's personality is projected into the inert body, meaning thanks to the experiment Barnabas' current adult personality is completely in place in Adam. Later it works that same way with[spoiler]Eve and Danielle Roget.[/spoiler]
And one could say that Adam has some of those other qualities that you bring up. Prof. Stokes was certainly cultivating them in him - and we've even seen Adam display reflection, particularly in regard to how he came to the realization that it was wrong to hold Vicki prisoner and that she should be released. But sadly, from this point on, all of Adam's inherited better qualities will mostly take a back seat thanks to Nicholas' influence on him, and the inherited personality trait primarily on display will be Adam's pigheadedness.