The PKI sucks. The value of bitcoin (and, more importantly, the bitcoin ecosystem) is the decentralized nature.
I understand the desire to have signed payment requests, but then you run aground of the whole key verification problem, which the PKI, if it were to work, solves nicely.
Unfortunately, it does not. Limiting to the EV CA roots doesn't solve this problem. You also open up a whole 'nother can of worms with OCSP as you noted in the gist.
Please, please, don't tie any part of bitcoin or the bitcoin ecosystem to the sinking ship that is the existing PKI.
If you must, generate the protocol and the user keys and prepare for the day when DNSSEC is more widely deployed so that users may publish their own certs in authenticated dns using something like DANE.