I haven't played this game in a long while....I remember having access to all my powers all the time as long as I had the endurance.  Well, there were a few active defenses and offenses that had cooldowns but have they added them to some of the really powerful attacks?

Since f2p, they have added Ebon Ruin for Shadow and Experimental Ray for Gadgets, none of them too powerful. You might want to wait for the heavy weapons framework which is supposed to have slow but strong attacks.