Crowd of enemies with UnitySteer

I'm experimenting with different libraries to make this work and UnitySteer looks very promising. My end goals:

1. Support for 50+ enemies

2. Enemies must follow the player and reach a specified target distance, then stop

3. Enemies must keep distance of at least 0.5 from each other

4. Enemies must surround the player instead of bunching up on either side

UnitySteer seems very powerful, unfortunately there is little to no documentation/tutorials on the internet about it. I know it's an open source project, so it is what it is. Here is my current setup, maybe someone can tell what I'm doing wrong:

Problems:

1. When the enemies reach the player they start freaking out and rotating on all axis, rather than stop moving altogether

2. I would like to disable rotation completely. It will be a sprite-based game

3. The movement is not smooth enough - they juggle too much on their way to the target

4. The enemies have "mass" - they accelerate and decelerate. I need them to move with a constant speed

Any help is much appreciated!