Try to avoid the use of _root, like you say it inhibits
future functionality. Try to target the correct scope of the
variable by using the "this" and "_parent" properties.
If you're really deperate you can user the _global prefix,
but i'd advise against it.
By keeping everything modularised internally and not using
_root or _global you prevent overrighting other peoples code when
working in teams, or leaving redundant code in memory when its long