Tor isn't exactly fast, most paid vpn service are faster for daily use. But still Tor has come a long way since its early beginnings I remember using it back then it was quite slow compare to nowadays. The rate of its development I would probably use it all the time in couple years time.
The other question regarding what ip shows up in B (OpenVPN service), if I am correct it would be the PPTP's ip am I right?
