Basically All characters are on follow.

You don't pass your default movement keys to your clones and you setup a diffrent set of movement keys to move your clones :-)

Its always best to get targets from a distance, so they don't have time to get in close and screw up your targetting. For warlocks this is obviously not a problem. If they do get up close, a good idea would be to drop a snare or some other crowd control method on them, get to a decent distance and blast them (Unless of course you can just AOE them to death).