I agree with Praetorian that only the essential spells need to be announced. I would add Paci to the list of spells to announce, however, as it's important for the puller to know which mobs are paci'ed and which aren't.
On my chanter, I also announce when my spells are resisted (mostly mezzes and the rare paci that fails) via a hotkey, because this normally means that said mob is headed my way and I might need help. It also helps explain why the mob I am supposed to be mezzing isn't quite mezzed yet.
My preferred method of casting and announcing is as follows. It's a bit of a deviation from the method described in this thread.
I mapped my keyboard so that I can cast a spell using the CTRL+NUMPAD(1-8) keys. For my Mez, AoE Mez, and Paci spells, I created a hotkey on the corresponding number that announces that the spell has landed. For example, my mez is in spell gem #5. My mez announcement is on hotkey number 5. To cast mez, I press CTRL+NUMPAD5 until it lands (working thru fizzles/interruptions/resists), and when it lands I press NUMPAD5 to announce that creature X has been mezzed.
I prefer this method because once you initiate a complex hotkey, you have to let it work thru all the commands on said hotkey before it will let you use another hotkey (I think). Also, it is impossible to predict how many times you will fizzle/be interrupted/be resisted before a spell actually lands and a pre-programmed hotkey isn't flexible enough for the odd times where you get several resists/fizzles/interruptions in a row.
I've used this method on about 100 adventures and continue to love it. It provides the flexibility to be able to interrupt the spell if needed and switch to another spell instantly, as opposed to waiting for the hotkey cycle to complete. It also can be done without a minimum of keystrokes and hand movement over the keyboard. I'm not saying it is the best method out there, and probably isn't for everyone, but I've gotten a lot of successful mileage out of it.
And I don't think you are limited to 3 commands per hotkey, but I might be wrong.