i usually play as a collectivist empire who see slavery as "giving a job" and can accept almost anyone...as long as you're happy (slavery - on every mineral\food, migration - off (ypu can't weaken empire by leaving the power plant i've assigned to you), happines <50 - purge)
unfortunately you can force people to abandoned planet(and call it New Siberia) ... you just will not have enough influence to do it. so Purge is the only option.
ps: diplomacy is almost non existent anyway in stellaris. so why should you care about it as a xenophobe? you will not loose much(and in fact you'll can a whooping 30% boost in "prove your point" argument)
unfortunately you can force people to abandoned planet(and call it New Siberia) ... you just will not have enough influence to do it. so Purge is the only option.
ps: diplomacy is almost non existent anyway in stellaris. so why should you care about it as a xenophobe? you will not loose much(and in fact you'll can a whooping 30% boost in "prove your point" argument)