What do you want ? Stay on your current Mac OS X version 10.6.8, but update the UFX firmware and driver ?
If yes: then you need to ...
1. connect the UFX via USB to be able to upgrade the Firmware to latest version 359/163/344/28 from 28.09.17
(firmware upgrades are not possible via Firewire !)
2. upgrade the UFX driver to version 2.21. compatible to Mac OS 10.6 and higher (32/64 Bit) in a separate step
which also give to you the latest version of TotalMix FX.
Your question in regards to WAV file batch processor.
The WAV file batch processor you need, if you want to extract all single tracks from a Durec recording. Although most of the major DAWs (i.e. Cubase) should be able to import the Durec file directly, which contains multiple audio channels which were recorded to this file in a "multiplexed" fashion.
Browse the handbook for Durec ... you can attach USB stick or disk directly to UFX (it has a special USB port in the front for that). Then you can use this for recordings in stand-alone mode without PC. Or alternatively it can be used to your usual PC recording to have a backup / plan b, shall the PC freak out ... Where PC recording can be with applications like DAW or also Global Record from the DigiCheck toolchain ...
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub13