2.2 fallback plan, please help

[thinkmega]

As I am much closer to root the phone, I need to put the final touch on my fallback plan. Here are the questions:

1. If I want to return to the pristine, stock condition of 2.1 (no root), can restoring VZW_A855_ESD56_QSC6085BP_C_01.3E.01P_SW_UPDATE_03.sbf
deliver the result?

2. As the result of flashing VZW_A855_ESD56_QSC6085BP_C_01.3E.01P_SW_UPDATE_03.sbf, please confirm SPRecovery would be removed as the result;

3. In 2.01 (the above rom), how can I force the OTA update?

Thanks very much!