Renaming nodes unsupported by combustion scripting

Hello,
I am very surprised to see that combustion can't automatically modify expressions path when you rename elements.
Also is there a way to locate where an expression error comes from? the little warning box tells me the bad expression, but not where it is...it's kind painfull for big or even medium projects.... (actually i got a
"- : Expression cannot be evaluated by JavaScript" message, it's a little ennoying to browse the whole tree!)

this is a big problem :
for example nest a comp and add a motion blur : absolute paths are wrong!
a workaround would be to use relative path, i think quickPick should implement this!! please fix it...