Not sure what you are now saying "STILL won't stay in safe mode".
Are you now saying you can get into that mode but it won't stay in that mode

Does Event Viewer have anything recorded for when you tap F8 as you switch on ?
There are other bcdedit cmds which could get you into those modes if you can get the bcdedit cmd accepted.
Try with both current and default as the identifier.
bcdedit /set {current or default} safeboot minimal
bcdedit /set {current or default} safeboot network