Were Paleolithic hunter-gatherers marginalized, was there warfare between the farmers and the hunter-gatherers, or was it less cut-and-dry and they just slowly assimilated? How much do we really know of the people that were there pre-agriculture? Was it a more dramatic change depending on where in Europe the cultural shift occurred?
How would the hunter-gatherers see the farmers and vice-versa?
This academic paper will be of interest. It suggests that actually they lived side by side for 2,00 years.