Condition:
ifplrtrail=1 - True when there is a trail left by the player in existance
Actions:
followplr=1 - Follow player trail if one exists
Also seen it used this way in older versions of FPSC
followplr
Turn on both debug options in the map editor to see the trail of the player and to see if your character is following the trail when you test the level.
Getting the character to fadeout will be done with a destroy script. You can see examples of those from the destroy scripts in your scriptbank/destroy folder. You will just need to determine how you want to sense the destroy of the character, either by range or etimer. then issue the runfpidefault=3 action to send it to the destroy script listed in the characters fpe file.
Examples threads: (these may need to be modifies, but will give you a start)
http://forum.thegamecreators.com/?m=forum_view&t=195839&b=23
http://forum.thegamecreators.com/?m=forum_view&t=142900&b=23
You can search using the google search at the bottom of the threads for followplr and it will bring up a bunch of links.
Hope this gets you in the right direction.