Your DB will need to be cleaned up to remove the incomplete chars. I have no idea if the incomplete chars could be a cause for the crashes. They might simply be a result of the crashes.
You could run world under gdb and get a backtrace when it crashes. In your server dir, run the following. You type the portions in red.
	Code:
	gdb ./world
...misc output...
(gdb) handle SIGTRAP nostop
SIGTRAP is used by the debugger.
Are you sure you want to change it? (y or n) y
Signal        Stop      Print   Pass to program Description
SIGTRAP       No        Yes     No              Trace/breakpoint trap
(gdb) run
...bunch of output...
 At that point you can start up your zone servers and then log in and try to create a character. When the process crashes, it will drop you back to the (gdb) prompt.
	Code:
	(gdb) bt
...bunch of output from backtrace...
(gdb)
 Post the backtrace output here and I'll see if I can help you further.