I'm not exactly an expert on the new codex just yet, but it strikes me that you have a lot of really killer anti-infantry, but not so much killer anti-tank. I assume the wraiths with D-Lords are intended to handle that issue, though with so much ranged glancing-power available to the army, it seems odd to have brought none of them for the heavy stuff (though I grant you the Tesla cannons will do just fine against things like transports).
All in all, it feels off not to have ranged gauss, but the more I think about the setup you have, the better it looks. Cheap infantry could pose a threat to your expensive Wraith units, but you brought boatloads of Tesla which should be able to kill off that threat where ever you need it to. Big gunships could be a problem, especially when going toe to toe with Annihilation Barges, but those sorts of enemies are prime targets for the Wraiths and I expect they would be one of the first things to be targeted.
The only thing that strikes me is that you have so much tesla in the army between the Nightscythes, Annihilation Barges, and Tesla Carbines, that you might consider switching out some Immortals so that your army has different options about what to bring to bear against different threats. With the mobility afforded by your Nightscythes, I don't think getting a unit of Immortals within 12' of a target will be very difficult, and I imagine there will be situations where a unit that averages 2 glancing hits on AV 11-14 or 13 hits from rapid fire (instead of 8 or 9) against a close-up enemy will be more advantageous than dumping more tesla onto it.
Just my two cents, but I feel like switching a unit of Immortals to Gauss Blasters, if only for the sake of versatility, might help. That said, redundancy has its merits too, and anything that can get done with tesla probably will in the list as-written.
Edit-> As for your suggestion, I'm not convinced that dropping a lord will help, if only because mobile CC is a big part of your win strategy. You have a lot of transports on the table, which will hopefully give you enough late-game mobility to grab objectives without drawing from your CC 'fund.'