Greybeard

Look in the menu under ISO. Auto ISO and movie ISO are both limited to 6400 but you should be able to change ISO manually to 12800 unless you are in one of the special modes.

Yes what AF Mode are you using and where are you placing the focus point? Do you see the camera appearing to focus where you want it? Are you using Focus Priority? Are you using face or eye detection? Maybe post a file SOOC (without going through any software) so that we can see the problem.

Note the instructions on the Fuji firmware site: "Check if there is no file with the same name in a destination of the firmware to save. If there is file with the same name, a browser can automatically change the name of the firmware like the name and (1). A camera cannot recognize the firmware correctly with a changed name like that." The firmware file name should be FWUP0019.DAT and it should be 48,914 KB in size.

You have misunderstood. The film simulation has not actually been applied to the raw data just the preview jpg and the metadata stored in the RAF file. If you open the raw file in many image viewers you will see the preview jbg with film simulation applied. When you process the raw data you can apply whatever film simulation you want.

Exiftool

I'm also interested - I found some for Nikon DSLRs on ebay and Amazon but not sure if they will fit the XT3.

I don’t think anyone is making you use Facebook on this forum - I don’t and seem to be able to read and post without problem

On playback my X-T3 does show the elapsed clip time. (While recording I'm afraid you are probably stuck with mental arithmetic)

Set aperture on lens to A and make sure Aperture Ring Setting in the Button / Dial menu is set to Command

What is your AF+MF setting (under the AF menu)?

I assume you already have the answer to this - you seem to be using a different ViewMode on the X-T3. If you set ViewMode to EyeSensor then you get image review on either EVF or LCD depending on whether you have the camera up to your eye. If that isn't exactly what you want then cycle through the ViewMode options until you find one that meets your needs using the little button next to the EVF housing.

Drive dial only

If you are having trouble reading or finding the serial number its written into the EXIF metadata of every image taken with that lens

You're going to need some intelligence at the storage end - when you plug the camera into the computer its the Fuji app or something else that pulls images to the computer.

The usual arguments against these cards are that they can move around inside the adapter and give errors and they are so small that they are easy to lose. They seem roughly comparable in write speed with the popular SanDisk cards. If you want to save money they may be worth a try. Let us know how you get on.