1 keystroke to 1 client and a different key stroke to another. I guess they could take exception to that but I think you could achieve the same results inside the wow api (maybe not in combat?). But if it can be achieved using the API (in and out of combat) it is only a convenience/simplification thing and wouldn't be an issue.

Round robin is possibly also similar style of issue, you can achieve the same effect using cast sequence. So I can't see that being a real issue.

If however either usesome form of logic based on external stimuli or added a delay... automation

That said I only bind keystrokes to the same keystroke in all clients, and so that they send all the time with no delay. I tried the focusless, leaderless thing... Its not how I play. I like having a definite leader with a succession plan.