Couple of problems I can see;
You need more long-range anti-tank. I would suggest two Infantry Platoons, consisting of two Infantry squads with a lascannon each, and the Command squad with a lascannon. That then allows you to take a fire support LR; the tri-heavy bolter setup is the most effective, given the BS3 of the gunners. Autocannon Sentinels would also compliment your Stormtroopers well, providing some mobile anti-skimmer weaponry.
If you want lethal assaulters, I would suggest swapping out the Callidus for an Eversor. He can kill anything in close-combat and the Deathcultists will back him up against hordes (his only real weakness).
I would suggest turning your Inquisitor into a good static firebase type. In the following configuration, he'll help prevent your lascannon firebases from being swamped by hordes, while retaining a plasma cannon to deter Terminators and MeQ's;
Inquisitor Lord, psycannon, auspex
2 x heavy bolter servitors, plasma cannon servitor
2 x Sages, Mystic
(198 points)
I would make the Chimera teams cheaper. Given their crappy BS3, dual heavy flamers are more efficient (because you'll be closing to that range when you drop off the troops). You'll want smoke launchers (so you don't get lascannoned en route). Stormtroopers are at their best shooting, so to make them more flexible I would equip them with a meltagun and plasma gun each. Also, I would suggest making the teams small, so you don't lose 200 points when one Chimera gets railgunned. Something along these lines;
6 x IST's, meltagun, plasma gun
Chimera, heavy flamer, hull heavy flamer, smoke launchers
(168 points)
