GordW

If your image frame numbers with the X-T5 are "99xx", my first thought is that your X-T5 is set for "Continuous" frame numbers and your card has run out of available numbers up to 9999. But, that your X-T20 is set to "Renew"
Go to Settings > Save Data Setting > Frame No. and choose "Renew". Reformat the card. 

Hope that helps.

Small and good: Nitecore FX-3

I think you will find the mode switch (by shutter speed dial) is in "Auto". When it is the "Auto" position there is only "STD" and a few B&W film simulations. Switching that selector switch off of "Auto" should bring back all of the film sims.

It's normal for an image taken with a different camera (especially with a higher megapixel count) for the images to be pixelated. The X-Pro1 is expecting 16MP images and it's processor and LCD are unable to correctly display the larger image size.
The 'present' icon is advising you that the image the camera is displaying was not taken with that particular camera. (It's a 'gift' from another camera).

It may sound weird, but more often than not a slow start up is the sign of an issue with the memory card. Try a few cards to see if you can narrow it down to one card in particular. Then, after copying any images you want to save off the card, re-format the card in the camera. That often resolves the issue.

The X-T30 does not support tethered stills shooting. That's reserved for the X-Tn single-digit models.
If you look at the menu option closely, you will see it says "USB MOVIE SHOOTING AUTO".