As far as I am aware the Lost Soul NPC type is functionally the same as the Custom type in terms of what it can do and what skill points it has. It does not have the same level/skill points as the PC that died. You can add a script I believe.
As far as I can tell they keep the skills, at least they used to. Can't be scripted though, its why they made new class for them. People were complaining about their ex-PC being scripted or something like that.
Lost Souls retain the player level and gain the "lost soul" NPC type skillset.
Edit: It doesn't appear to be displayed on the rules, presumably since lost souls can't actually be hired like the other NPC types, but it's the exact same template as for most of the civil types of NPCs, like potential mayors and such.
Edited By: Syn on Year 16 Day 246 15:45 ____________
Technically, I have no ability to tell if you have access to it. However generally you don't know it is a lost soul unless you've seen it. However if people do complain that someone claimed it with no access that will be severely looked at.