I like those abilities! And no, not a speed tank xD he's more of a dodger, or even better, a 'take them down before they have a chance of getting a hit on you'. 

However, since he will be HEAVILY dependent on dodging as any heavy hitter can take him down in 1 shot, would it be possible for his movement speed to be able to stack with his attack speed, but not vice versa? 
For instance, he runs so he gains movement and attack, then attacks and gains attack speed. Then he runs again gaining movement on top of his already aquired speed, but his attack gain is reset, and when attacking his attack speed is reset as well.
So basicly it's like: as long as he either moves or attacks, his speed keeps rising slowly. Maybe it could be a feature of the gun boots?