For starters you might wanna post this in forums as opposed to a snippet, but heres a few solutions you might try.

• Instead of all "if" statements change all but one to "elseif" reason being is that you could have op, halfop, and voice at the same time, echoing it 3 times on your end instead of once. (Can refine this method to function in one alias, but that is by far more complicated than changing a few statements)

• Your not silencing the "msg $active $1-" so your script echoes your message with the proper symbol affixed to it, while messaging the active channel with the same thing -- Hence why you can see it twice.
  just append a period (.) to "msg $active $1-" and your echo should stop