Ray, Would you like a ham sandwich? because it is clear you are not listening to anyone here.
Or more specifically, only to two people here.
Saves: Get over it? Just because YOU don't like it does not mean everyone else does not like it. Also, unpredictability is a natural part of the game because we use DICE. If you want predictability, play rock paper scissors. You are suggesting to take away a simple, different mechanic for something WAY more complex.
Inertialess Drive: You contradicted yourself there. You say you don't want DE or space marine+, yet your rules just suggested the same. AAF for necrons are supposed to get escorts to their attack points quickly, and to get cruiser vessels out of tight spots. Stop trying to use it like the navy!
Lightning arc and gauss batteries: Well, your desire to make something new is certainly interesting, however it's clear you don't believe the Orks exist. Strong work. Also, you have not given a good reason yet to replace the current weapons systems aside from 'I want it, so I am doing it'.
Sepulchre upgrade: I admit, giving the shrowd a sepuchre would increase it's usefulness, and let you use the terror field far more often.
Pocket dimension: Die in a fire, the tombship is SUPPOSED to be the most powerful ship in the game. It is the BATTLESHIP of the MOST ADVANCED RACE IN THE GAME. It is not supposed to be cheaper or weaker then a retribution battleship!
Scarab swarms: Not a bad idea, won't question it.
Crit table: Drop it. Taking away the crit table takes away part of necrons unique.
Ray. You need to stop, right now. This is becoming the same disaster that Bakka was when it was nothing but "My way or the highway". I have shown your suggested upgrades to my fellow players, and ALL of them think what you are doing is insane.
Quite simply, Ray... Drop it.