It's been awhile since this ability was changed, but by your own standards, the ability and morphs are much weaker than similar abilities present in the game. Why is this ability and morphs under budget? Simply look at the bow equivalents to see what I mean.

Destructive Touch (focus on fire)
- 15m range (just.. why?)
- fire knockback (short, 3-5m or so, not sure)
- direct damage (damage matches first hit of a dot based abilities standard, about 50% of a spammable)
- 2700 cost (spammable standard)

Magnum Shot
- 22m range (cc/chain/gap closer standard)
- knockback (8m!)
- direct damage (about 75 % of a spammable standard)
- 3500ish cost (cc/aoe standard)

So magnum shot knows what it is and because of this, it's balanced properly. It's a ranged cc, the cost, knockback and range make sense. Damage is competitive, not as strong as a spammable, but not as weak as the first hit of a dot based ability.

Clench doesn't know what it is because the other morph is suppose to be a ranged dot and this morph has to do 3 different things depending on the staff. It has the cost of a spammable, but really weak direct damage because it thinks of itself as a dot based ability, and it is short range that doesn't match the cc/chain/gap closer standard. It doesn't knockback targets as far either.

Destructive Reach
- 28m range (standard)
- 2700 cost (standard)
- direct DMG, roughly 50% of spammable (standard)
- dot DMG, roughly 100% of spammable (standard)
- no auxiliary effect (below standard, see poison injection!)

Poison Injection
- 28m range (standard)
- 2700 cost (standard)
- direct DMG, roughly 50% of spammable (standard)
- dot DMG, roughly 100% of spammable (standard)
- up to 100% damage when below 50% health (auxillary effect, standard)

So when you compare these 2 abilities, you can see their almost identical in every way, except the Reach morphs only auxillary effect is that it becomes 28m from base, that is NOTHING and shouldn't be treated as the morph effect. It has nothing that makes it special in comparison. Maybe it would be a bit of a copy and paste, but at this point... Why don't you consider making reach include execute damage too. There is no Magicka universal execute available and I don't really understand why ZOS is so against this.

These 4 abilities were the easiest to compare because they're the most similar. I'm sure you can get into the frost/shock aspect of Clench, but one thing is clear, the morphs are a mess.

Clenches damage seems to stem from the fact that it USE to be a dot which explains why it's so weak. The cost matching spammable standards seems to drag every aspect of the ability down. I would suggest matching the cost to aoe standards (1.3 times?), bumping up the damage to at least 75% of a spammable and increasing the range to 22m. This will ensure it works more like magnum shot (fire), while also making the ice/shock versions of the morph (barely used) more competitive. Don't even get me started on how weird it feels to use a 15m ranged ability.. it doesn't match anything in the game. I thought we learned our lesson when you reworked DK ranges.

Reach brings nothing new to the table and Clench tries to be 3 different abilities in 1. All of these problems started when the morphs were reworked. ZOS needs to revisit these morphs again.