I don't care that he is rich as Croesus. I get the impression he has been a complete bastard to his wife, but that doesn't (necessarily) mean he can't be a decent MP. I don't even really care that he is an eco-nut, because parts of what he believes is self-evidently sensible, and the global warming gibberish he swallowed has been shown up to be fraudulent and compromised by scientists whose income is wholly dependent upon propogating the myth of AGW.
No, the reason I wouldn't vote for Zac is because it turns out he's non-dom. Is there any reason why the voters of Richmond should vote for someone who proposes tax policy for po' white folk, but which will barely affect their representative? He could probably find the £30k non-dom levy in the back pocket of the last pair of Villebrequin shorts he wore in the Med this summer, or in coin in the Goldsmith laundry's tumble-dryer.
I believe that it is every man's duty to keep the Treasury as far away from his loot as possible. But the non-dom route is also the non-qualified route.