Fr. Wegner, in my opinion, is very German. He has an extremely serious appearance, and he is quite disciplined and orderly. But he can be warm and surprisingly funny.
I've never seen him angry but I've heard he can be vindictive, as when he publicly dressed-down Fr. Fox, and at other points, various other Résistance supporters. He is also a 'company man' in the German mold, and an ambitious one; he spearheaded the re-branding. He's no friend of the Resistance and the odds of him becoming one are about as close to nil as one could find in the new SSPX. This is part of why he's being promoted, needless to say.
Is he a liberal? Evidence points to the affirmative. Aside from what I've already recounted, his sermons are typically devoid of militancy, and socially he appears to favour liberal priests and laymen. Take these last remarks with a grain of salt, however, as they are just one man's observations.