Control in any game that is not City of Heroes is going to feel massively nerfed compared to CoH. CoH was the only game I've ever encountered that let you stun lock a single enemy forever from level 1, let alone two or three. That's a topic with enough depth I could write an entire novel on it, but the bottom line is that if you liked playing Controllers or Dominators, you will not find much refuge out there in the cold, harsh world.
Buffs are more rare in CO than they were in CoH, but they're good when they're around. Debuffs are more common, and range from game-changing to I-didn't-even-notice-they-were-disoriented. A good debuff character in CO is like a good Corrupter in CoH: insanely valuable to have around, but you might not notice how much they were doing until they leave.
I haven't gotten the hang of tanking or Healing in CO, yet, but my Tank is only level 12, and the only Heal I have any experience with is on a Grimoire, so it's just the one Heal, and that's not her primary job. So far, the impression I get is that Tanks are squishier here, and it's harder to hold aggro, but they deal more damage. Heals... I really don't know. I'll get back to you on that.
As far as spamming the same two powers... yes, part of that is that you're still just level 14. I mean, you've only got four click powers, yeah? One slotted passive, one Form, your energy builder, and then three actual attacks. That varies greatly from Archetype to Archetype, though: the Grimoire gets a summoned damage patch and a PBAoE with knock by level 14, neither of which radically changes how you fight things, either in a group or out. Whereas the Behemoth gets a leap attack and a Hand Clap, both of which are huge QoL improvements for a melee character, especially a tank. At the end of the day, yes, CoH's power system made for more dynamic combat, but also keep in mind what it was like firing the same two or three powers over and over again at level 10 - you had a lot of dead space in combat when things were recharging. CO doesn't have dead space, just time where your blasts get weaker for a bit.