When logging am I W3UC/QRP or W3UC ? I assume this makes a big difference for LOTW awards although I cant seem to find much on LOTW QRP and awards.
This part depends on what you're logging with. W3UC/QRP is your call plus the fact you're operating QRP but QRP only means low power, not how much power.
Some logs provide a place for the power output. Some logs don't provide a space for YOUR call. This information is entered either on the cover of the log or the beginning of the log. Electronic logs do provide a spot for your call.
The best thing to do is pretend you are the one receiving the QSL and see if all of the pertinent information is there and is it understandable.