All Combo Skills On One Hotkey?

Basically, Aion.

For those of you who don't know what I'm talking about, in Aion (MMO) you have chain skills kinda like in FF14. However, when you use the first skill in a combo, that skill on the hotbar turns into the next skill in the combo for a limited time. Thus making it far easier to manage your hotbar because you aren't clogging it with 2 combo chains.

For example, as Lancer :

You have True Thrust on your hotbar for key 1. When you use it, key 1 turns into Vorpal Thrust. When you use Vorpal thrust, key 1 turns into Full Thrust. Once you activate Full Thrust, the key turns back into True Thrust.

How would this work for say monk who's abilities combo to about 3 different abilities

You could write a macro for it. You just won't be able to continue the combo if you had to stop midway through for whatever reason. As far as I know, xiv's macros don't support conditional actions.

It sounds good at the onset, but it's exploitable, and won't be robust enough to work in all circumstances without a complex priority system as well.

Exercise, bind these to a key:
Haymaker
Bootshine
True Strike
Snap Punch

You don't need Haymaker, but it starts to show why this is abusive. So you have a single button that runs through an optimal damage rotation based on effects active. The API needs a way to know if a skill is "valid/preferred" and progress to the next skill if not - it usually wouldn't be implemented the same in code as the range or "active" border in the hotbar. Draw the state machine; your API needs to provide a lot of detail in order to progress accurately.

For the other classes it's a bit simpler. Take a conjurer, I want to cast Thunder, Aero, Stone. Those aren't combos, but I'd still like to use it the same way. I get hit during this macro exchange; then what? I suppose a 2 second timeout and reset. Clumsy.

Interesting... i need more info on how this can be done lol... playing on laptop w/mouse using these macros are a pain sometimes...