Something else that might help things go a little more historically would be a DHE for the sale of Neumark, so that if the TO is low on cash (or fits some other set of requirements) then Brandenburg gets the opportunity to purchase it. Of course it's somewhat rare that the TO doesn't lose Neumark in a peace deal fairly early on but it would still be an improvement.
Yes, because Brandenburg has a core on it. Which is weird, because selling provinces in game removes said core. The DHE would probably be the way to go.