I like the gameplay of the catalyst, but there is a lot to work on I think.
1) As said before on this thread the hammer skills themselves are really to slow, the best example is earth skill 2. The dmg output you get from that is just not worth it.
2) the duration of the third skill on hammer could be a bit longer. You can use max 2 skills and you need to swap attunements to activate it again, or it's lost. The reward you get from eventually using grand finale is to low, even with 4 projectiles.
3) I feel like the hammer skills themselves got almost no combo's. Skill nr2 from air and earth could be a whirl. Now we have only 4 blast finisher's, which is nice, but without a combo field other then the f5 skill it's kinda hard to get combo's in, when this spec is all about combo's for aura's.
4) I think there should be a trait that let's the f5 skill follow you, making your "melee" precense a bit more terrifying. Anyone can now just walk away from it.
5) Maybe make the 2de skill of hammer a target skill. Like rapid fire from ranger (longbow) If the enemy is moving, they take only 2k dmg max? That's just not worth it.
6) 4th skill of hammer on fire could be a combo field. When i see an enemy catalyst use it, i can see 4 kinda "lava fields" on the ground, but it's actually nothing.
7) The utility skills are not really making a bit difference when people can just walk away or dodge out of your f5 field. The range of hammer is to low to make up for it.
The utility skills could maybe affect the energy field? ex.: When the energy field is up and you use the earth utility skill it could reflect projectiles. But when standing in the energy field, you get also a 3k barrier. Using the water utility skill could heal for 4k to anyone in it and grant aegis... These are just some idea's to make it feel more rewarding or usefull.