This is an older style flash that has it's own built-in auto-exposure sensor on the front of the flash.

In your photo you have the flash set to ISO 100 and f/4 auto-exposure. The W(28mm with a diffuser) N(35mm) S(50mm) T(85mm) switch corresponds to the flash head position. It adjusts the flash sensitivity to the flash head position. Modern flashes due this automatically but older flashes are all manual.

Always use manual mode on the camera. If you want to use ISO 100 and f/2.8 with 1/60th shutter, just match those settings on the flash and it will give you auto-exposure.

At ISO 100, the 3 position switch on the front is basically the power output: Full Manual Flash, BLUE(f/4.0 Auto exposure), RED (f/2.8 Auto exposure)

At ISO 400, the 3 position switch on the front will change to: Full Manual Flash, BLUE(f/8.0 Auto exposure), RED (f/5.6 Auto exposure)

Match the ISO on the flash to match the camera. (note: the Blue/Red f/stop values change with the ISO setting)

The distance range shows how much "reach" the flash has depending on the ISO and f/stop selected. As it is set now, the "Flash coupling distance" is about 2-14 feet. If your subject is less than about 2' it will be overexposed because it is too close, and if it is more than about 14' it will be underexposed because it is too far away.

I would bump up the ISO to 400 on the camera and the flash so you have more range.

If you want to shoot manual flash, you should match the f/stop to the subject distance. In your photo above, at full manual power, with a subject 40' away, you should use f/1.4 and if the subject was 5' away, you would use f/11. Changing the W-N-S-T switch would increase the flash coupling distance because the flash beam would be narrower and reach farther in the T setting.

"Multi-Dedicated" means it should have a "S-O-N-C-P" switch that let you select Standard, Olympus, Nikon, Canon, or Pentax dedicated functions. This could automatically limit your camera's shutter speed to the max sync speed and maybe show a flash ready icon in the viewfinder. In your case I would just use "S" for Standard but it is possible that one of the other manufacturer settings could match the Fuji protocol as well.

I couldn't find a manual for it but this is helpful: http://dpanswers.com/roztr/flash_show.php?id=419&pid=MR630CD