172 Driver,
CDU Preflight was completed for sure and we had a target N1 as I remember including this value in my breifing. However, I cant recall if the OAT was entered. But if the preflight cannot be completed without entering an OAT it must have been entered. Could possibly be one of those once in a while things or the MCP Autothrottle switch is about to go U/S.
As for unpressurized T/O after de-ice, our company's SOP is to perform this procedure(found in FCOM 1 Supplementary) to avoid fumes entering the cabin. Might not necessarily be a Boeing procedure.
Thanks all.