Things started well but now .19 FPS and slowing

[Selur]

I meant to ask, is is possible to just do the de-interlace without encode so I can play around with different encode settings?

Aside from exporting to a lossless intermediate format: No
Deinterlacing changes the video content, so you can't simply 'patch' the input format in a lossless way.

'Filtering->(De-)Interlace/Telecine->Deinterlace/Telecine Settings->Analyse' is a heuristic which can be easily wrong.
=> best look at it with your eyes. (read: https://forum.selur.net/thread-3010.html and also read up on interlacing, telecine and field-shift and norm conversions)

Cu Selur