Switching the healtances to blaster is a good idea for the reasons you mentioned but also because S8 IDs paladins, wounds dread knights on a 2+ and more importantly lets you dance out of his 24" threat range.
Might be worth considering dissies on raiders, they normally do quite well even if they only fire once or twice.
Inccubi could be an option, but paladins have 2 wounds a piece so they will still be able to fight back. I would be more inclined to go for a husk archon. The Husk archon should be able to slice and dice really well once he get's his first soul.
Personally I would keep the grots, drop the aberration and run them with a husk archon and a liquifier. Despite being vulnerable to instant death Grey knights can't use hammer hand and their force weapon in the same turn (so they will have to wound on 5s), more importantly you will lose most of the grots to greyknigth dakka anyway before they get IDed in combat. The grots give you a reliable way to get your archon into combat. Also if you get into combat and you only have a single grot left and the archon, you should use your shadowfield to tank saves (as that way you will keep your T5, and that's will stop more wounds over time then letting the grot take the instant death wound). Also remember that FNP still works against against force weapons I believe as they only trigger once they have wounded you.
Hope that helps, good luck and I look forward to the report if you plan on doing one.
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Latest Report: BR4: The Repugnant Ramblers Vs Imperial Knights - 1250pts
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