1850 a bit of everything Mech list

First off, I like the list only a few things:
What is the Psyker Squad doing??? They could damage enemy moral, but I think you should drop them and get a Russ Battle Tank to supplement your executioner.

The Executioner is built to destroy the enemies heavy/elite infantry (or weak tanks), so the lascannon is misplaced. Drop it. Give that squadron hull heavy flamers instead of a heavy bolter. It'll help keep assault squads off you.

I think you CCS would do better joining the Chimelta squads, so give it Meltas instead of Flamers. And giving your commander a power fist means that you can assault to finish off any persistant enemies.

I also think you should consider giving your PCS wings and have it join the rest of the Platoon. Together they can deploy on objectives and the junior officers can issue orders to the squads to increase effectiveness. Those squads are built to assault, so you should give them a few things to help, mostly power weapons.

The Gun ships should all be anti-infantry. Your Chimeltas should be able to deal with any enemy tanks, and your executioner and manicore will deal with any tanks that might escape that. Your gun ships should be built to kill hoards while transporting your troops to the ojectives ASAP. I think the missile pods help, but the heavy bolters add very little to the ship.

The Devil Dog is not gonna help much with three melta transports, so use it to supplement the PCS's Valkyrie.

That should leave you a couple of points to spread around. I suggest making sure all your squads can hold their own in an assault.