DC, and of course you would have supported HindenBURG. You're a calvinist monarchist, I fail to see how you could have voted for Marx whose his party was relatively pro Weimar republic (even if it became a bit rightwing after 1930). And he was catholic. The catholic/prostestant divide was important at this time.
Since he is a constitutional monarchist rather than a dictatorial one, I would think DC may have fit well in the DVP.
http://en.wikipedia.org/wiki/German_People's_Party
No, the DVP was a pro free marketer monarchist party. That's not DC's views. Although he would have supported his candidate at the first round.
DC would have been fine with the DNVP, but with the pro Bruning faction after 1930 (Trevinarus)