DE do have Mimics to assist, and with a higher Attack Rating would likely have the first turn. So in a game with 15cm (90cm gap between fleets) deployment vs IN, I find my general strategy works something like this;
1st DE turn: AAF towards enemy, and are now ~50cm closer.
1st IN turn: Drift aimlessly forward minimum distance ~10cm closer.
2nd DE turn: Now about 30cm from the enemy, I move forward, turn and do not fire as Mimics still work. Gap is now 0cm (so we're right next to each other).
2nd IN turn: A smart player would AAF or use Come to New Heading, but this probably won't help much. They can't attack you still.
3rd DE turn: Lock on if possible, turn at start of move and follow poor IN ships in rear arc!
Another funny method of doing this is that since DE ships have Nimble, I have often found myself ~30cm in front of an enemy, and much to their surprise used Come to New Heading to pass them then use both turns to make a 180 in their rear arc. Here you would use leech torpedoes and fire to prevent their turning ability. Damage isn't critical at this moment, just preventing retribution.
About the CL fleet concept. You see this with the Wardens IN fleet, and I suppose that a more CL heavy DE fleet is sensible, but still it would seem that a pirate fleet would still have some smaller ships. IN CL fleets in the fluff generally have a number of supporting Escorts, even moreso than Battlefleets or Cruisers. Most scenarios involving Cruisers of Chaos or IN races rarely are accompanied by Escorts, whereas IN CLs are always described as having a number of Escorts.
@Horizon,
The Eldar player doesn't support MMS unfortunately, however he still has convinced the rest of the group to support it.... through douchy MSM playing.