You made the right choice. Wrath is hot garbage and Laid Bare is god tier.
You could, I guess, make an argument for speccing Wrath for bossing against bosses without adds. It’s going to be a very small buff though - adding gun damage to a zerker Amara isn’t really all that valuable, especially if you, in a bossing build, are using a 250 or 300 cast/slam annoint (which are also gun damage).
I posted a build doc yesterday, I explain how the 300>90 annoint is the best annoint in the game, particularly for Zerker Amara. Give it a read if you like! Short form: it double-dips (or more, with Splash or Indiscriminate) with TTB giving insane multipliers.
I’m running full 5/5 Do Harm with TTB. When you grasp an enemy with TTB, it will create links to other enemies. If you shoot the grasped enemy, it will receive gun damage but the linked targets will receive the damage as Action Skill Damage. On Mayhem 10 with lots of badasses and cartels, this is an extremely potent mobbing combo.
You can take out points from Restless to Do Harm. Cooldown Recovery has diminishing returns, so if you have +35% Cooldown Recovery on your Phasezerker, you definitely don’t need any points in Restless. Just do the math and you’ll see it’s not worth it as you will have barely any TTB downtime with Avatar and that 35% CDR, especially with CDR points into Guardian Ranks. Just remember NOT to augment your TTB with Stillness of Mind.
On the topic of Echo’s build, you can make it even more effective by only taking 1 point in Sustainment. You will heal like crazy with all the DOTs and the high damage of your gun. Remember that your HP is still the same as M0. Spec into Soul Sap so you don’t receive any damage or cooldown penalty with TTB.