Greetings,
How many abilities do you want/need?
Let me elaborate:
In AoC we have the weapon attack, a block and a dodge roll baked into every character. This means 3 buttons are already allocated to specific tasks during combat.
This leaves us with less buttons on the keyboard that in WoW for example to key-bind abilities.
(Given that you are not a tank, you might unbind block to free up a space.)
We also have a sprint option that most likely takes up ctrl or shift. Cutting down 1/3rd of the usual hot-binds (example shift + 4)
The most comfortable to reach keys are… E, Q, R, F, C, V, X, Y, 1 to 5 (maby 6). Honorable mention to T, G and B, but B is for Bags change my mind

We have 13 confortable to reach keys and 3 are taken, leaving us with 10. Multiplied by 2 for the shift or ctrl keys makes
20 comfortably usable slots.
Ashes have stated that macros are not intended to be necessary to have a coherent rotation.
The weapon attack is supposed to be your filler ability, and it has benefits to finish a combo to get effects (as shown in the ranger update)
All this makes me think that the rotation and situational cooldowns in AoC should not be as convoluted and that
less is more when it comes to abilities.
I think you should be able to decide what abilities fit your playstyle and only be able to choose or talent in a select number of abilities. This would cut down on rotation bloat, refine your character identity and lead to interesting choices along the way.
(Example Ranger: do I choose to specialize into barrage and be mobile while shooting, or choose to talent the stationary snipe for big dmg, but must have a snare in my kit to keep distance? Or try to have both but lack in another department)
I solemnly believe this would bring out YOUR identity.
It also ensures not every class will feel the same, because you cannot take everything and might need others to help elevate your weakspots, when facing tougher foes.
Less abilities also means that 1. your weapon specialisation tree with its combo system has time to shine and 2. every ability press is deliberate and has weight to it. No longer are you mindlessly pressing a rotation, you are choosing to use your CC or heal-cut. You will still have press on CD abilities, but maby you speced into a bleed and can proudly say you have 100% uptime on it on enemies whereas another player can’t, but he can bleed multiple enemies at once.
For those who say, but MMOs need many abilities to be interesting I say, we have seen so many interesting combat systems with way less. V-Rising (6), League (4 + summoners and items), Overwatch (3 + ult) those are the most prominent that come to mind.
And I don’t want AoC to have only 4 abilities per character!
I just want the
experience to be streamlined by the talent choices the player makes.
I think a Player should realistically only have to use and spec into 12 abilities out of all the abilities he is presented. That’s enough for 2 rotational spells, an AoE, mobility, def CD, dmg amp spell, CC, interrupt, heal and an ultimate (like the bard and warrior had) throw in 2 buffs/utility and you are done.
That’s a fairly good distribution, and if you want to have more of something, you now have a choice to make.
There would have to be restrictions on how many of one you can take (CC-bot prevention).
Using less of the confortable to use keys opens them up for other things too, like C for Character window.