They offer "ID Verified" certificate on some courses for a small fee, certificates which should be more valuable than the regular ones. However I don't think they're accredited.

No, but they are doing a new program-of-study (beyond a single course) certificate program called the XSeries Certificate (MITx is offering two of these, a 7-course one in "Foundations of Computer Science" and a 3-course one in "Supply Chain Management")