Code P136, P0300 and P0705 question.

[cowpie]

Greetings,
My code reader shows a P136 (O2 sensor Bank 1, Sensor 2) and P0300 (Random Misfire). Stupid question #1 Do I need to replace the O2 Sensor (appx $65.) assuming the connections are good?. #2 Could the Random Misfire be associated with a bad O2 Sensor?.
Stupid question #2 I also had a P0705 (Trans Range Sensor. The Trans Range Sensor appears to be the Vehicle Speed Sensor in Chilton's. I have had what I think is TCC problems and after disconnecting the D wire (Thanks for that one) problems seemed to disappear. Could the Vehicle Speed Sensor affect the TCC as to look like a TCC problem?
Once again Thankyou in advance.
Cowpie