Conform will give you slowmotion footage.
Do you want that?
If not just create 50fps prores and just drag it in the 25 timeline. You will loose half of the frames.
Seems like a thumbnail caching issue.
Start with trashing your fcp prefs/cache files.
Google fcp preference manager. Its free.
If its a timeline issue, then copy paste your edit in a new sequence with same settings.
Thats crap. When i watch tv, 75% i see is cheesy.
Its the person behind a tool that makes something cheesy or not. And its also a matter of taste ofcourse.
Blaming a tool for cheesyness is just weak.