"Jemimah" isn't dead because Caspian is/was Jemimah.
"Caspians" father isn't dead because "Caspian" made him up to try and legitmize himself. A fraud however, cannot be legitimized by making up a new character and killing them off.
Caspians "wife" isn't leaving him, because she isn't real either.
Caspians "sister" can be a hardcore witness one month, and then a inactive-for-2-years-witness-26-year-old-practicing-doctor the next month, because she to is just a figment of the fraud Caspian has perpetrated on the board.
His motives? I haven't a clue. My best bet is that he's just a sick puppy who likes to play puppeteer. BUT, it could be worse than that, so if you've given him information, do what you can to protect yourself.
BTW, if any of the above seems like wild speculation on my part, it isn't; you just haven't looked at the evidence. This isn't brain surgery, or even forsenic science, and I aint Sherlock Holmes. It's simple human behaviour, and the evidence (or 95% of it, a small portion of the evidence is behind the scenes and private to other posters) is right out on the open on this db for anyone to look at.
My last word on all of this.... is that for whatever reason/s, it seems a good many otherwise normal posters seem to think maybe it's kinda OK for people to make shit up about themselves, y'know, stretch the truth into a gooey mess, and the db and posters in general should just have to deal with it.
It's not OK. Shakespeare had it right.