I think you're suffering from the classic first-time ISBoxer user problem of confusing mapping & repeating. By default, ISBoxer does mapping so it isn't going to pass the modifiers through to your slaves unless you make the mod+key a hotkey also.

That said if you're trying to make every single ability of every toon available on a separate key sequence, you are definitely unnecessarily over-complicating things.

  1. Create a starter macro for your tank and each DPS toon that gives them a half-way decent rotation. Don't try to max your DPS output; you'll just give your tank aggro issues.
  2. Assign the macro to the same key press on all you damage dealing toons. Use one of the keys map the ISBoxer wizard created for you so that you get an FTL setup for free
  3. Either use a healing addon (e.g. Vuhdo, HealBot) and repeater regions, or create a set of 5 macros that explicitly heal each of your toons and assign each macro to a separate key. Remember not to assign them to the dps key
  4. Try working on non-elite mobs: one at a time, then in groups, then try an instance. Be prepared to die a lot at first.
  5. Once you're comfortable with all that, then start adding other things to the mix