Hi Nicholas, welcome to Mizahar. It would be fun to roleplay ghosts, so let me help you with your questions:
1. Are ghosts visible at all times, or only when they are Materializing?
They aren't visible to regular humans unless they materialize. Of course there are certain skills that allow other individuals to sense the presence of a ghost like people with skill in Spiritism or Auristics.
2. Obviously Ghosts don't wear physical clothing, does that mean they can change what clothes they seem to be wearing?
Yes, but this would take skill. Practice Materialization more often!
3. If yes to the above, can they also change their appearance? So that they can change from looking like a young self, to an old self?
Based on the wiki on
Materialization" Moreover, ghosts can only materialize one of their usual forms; they cannot make up new ones on the spot." And on the
Ghost wiki: "A ghost tends to resemble its former self when it was alive. Whether it chooses to look like it did just before death, or some other version, depends on the individual ghost and what occupies its mind. Ghosts who wish to avenge their deaths often showcase their wounds in gruesome ways; those who died more peacefully will likely choose a more elegant façade to represent them."
I hope that helped! For further questions, check with Tarot and see if he can provide you with details.
4. How are Ghosts tolerated in Syliras and Zeltiva?
I think that in most populated places, since the wiki states that ghosts are "common" they aren't too strange and aren't really too rare. But of course, certain kinds of people would still be spooked out by ghosts, and some others who hunt for ghosts might be out to "dust" them. Read the
Spiritismlore and check dusting ghosts section.
5. Obviously Ghosts don't eat regular food or light fires, so do I just... not list up that in equipment in my CS?
I am pretty certain this had been asked before, and the answer was that ghosts can have possessions, but it would be a bother, specially if they have no means to carry it around.
Hope I helped! Look forward to seeing you roleplay!