Is delay allowed?

[mbox_bob]

Actually I am doing the same. My program stops sending queue for some time and then continue to process sending queue.

I call it "delay" and may be it is wrong word but I guess Blizzard doesn't care about words.

Aye, they would not mince words. It would be called a bot. Because with enough stopping and continuing of the "sending queue", and the appropriate keystrokes being queued up, you could start it off, walk away from the computer, and the toon will continue to play the game all by itself. This is pretty much the definition of a bot.
You may not be taking it quite this far, but how are we to know? You yourself must realise all this already, otherwise you would have posed your question on Blizzard's forums.

I tend to agree multi step isboxer keymaps specially with "Do not progress to the next step for X time" is indeed the same as a delay

No, ISBoxer's implementation of "Do not progress....." is not the same. It does have a progression delay in the switching to the next step, within the ISBoxer configuration, however it DOES NOT EXECUTE the next step all by itself when that delay happens to have expired.
If you start a mapped key sequence in ISBoxer, and walk away from the keyboard, it will never finish that sequence, because it requires you to press the hotkey to progress the next available step. i.e. it stops sending any keystrokes to the game the moment you stop pressing keys on the keyboard.