1) you will need LOGDAEMON.EXE so that (Ring 3) applications can use the "LogAddEntries" API to write to the System Log. Not many apps need it but it does not hurt to have it running. "LogAddEntries" API is only documented in the Debugging Handbook.
2) you will need LOG.SYS so that Ring 0 device drivers/IFS etc. can use the DevHlp_LogEntry device helper to write to the System Log. It is also required by LOGDAEMON.EXE to operate. Not many device drivers use it (if any) but it does not hurt to have it running
3) You can safely remove all that EP... stuff as it is the outdated FFST stuff which has been superseded long ago, see here:
https://www.edm2.com/index.php/First_Failure_Support_Technology/2From the list, only
keep the following as actually, that
is the new FFST stuff (I will need to recheck just to be sure):
FFST.EXE
FFSTCONF.EXE
FFSTPCT.EXE
ERRLOG.DLL
FFCONFIG.DLL
FFDUMP.DLL
FFGUI.DLL
FFIPC.DLL
FFPCT.DLL
FFPROBE.DLL
FFST.DLL
FFST.HLP
4) FFST.EXE is the system log daemon, it is started by SMSTART.EXE (see what THESEUS.EXE reports). It seemingly replaces EPWDDE3.EXE, EPWROUT.EXE, EPW.EXE.
5) Finally, FFST.DLL contains routine "FFSTProbe" which effectively supersedes "LogAddEntries" (see above) to write to the System Log but both still coexist where "LogAddEntries" is easier to use but requires a handwritten DLL to format the logged data where "FFSTProbe" uses a text template formatting approach that however is overly complicated.