Balanced IG List 1,850pts Any help appreciated.

[Genevaman]

1850pts

-HQ-

Company Command Squad - 185pts
-Vox Caster
-Regimental Standard
-Medic
-Officer of the Fleet
-Chimera (Heavy Flamer, Multi-Laser)


-ELITES-

Guardsman Marbo - 65pts


-TROOPS-

Platoon Command Squad - 50pts (x2)
- 4 Flamers

Infantry Squad - 105pts (x2)
- Vox Caster
- Grenade Launcher
- Autocannon
- Commissar

Infantry Squad - 65pts (x4)
- Grenade Launcher
- Autocannon

Veteran Squad - 170pts
- 3 Plasmaguns
- Chimera (Heavy Flamer, Multi-Laser)

Veteran Squad - 100pts
- 3 Meltaguns


-FAST ATTACK-

Vendetta Gunship - 130pts

Sentinel Squadron - 120pts
- 3 Scout Sentinels
- 2 Autocannons
- Heavy Flamer


-HEAVY SUPPORT-

Leman Russ Battle Tank - 185pts
- Lascannon
- Heavy Bolter Sponsons

Leman Russ Demolisher - 210pts
- Lascannon
- Multi-Melta Sponsons


There's still 115pts in limbo at the moment so any tips on where best to spend it would be appreciated.
The main idea of the list is to form a massive gunline with my infantry squads while harassing my opponent with outflankers and infiltrators such as my Sentinels and Marbo.
A steady advance with my Russes and Veteran squads should put pressure on my opponent whilst my Vendetta (with Melta Vets) swoops in and deals with some of the heavier vehicles mid-game.

Against light vehicles I should have no trouble thanks to the sheer volume of Autocannon fire I'll be bringing to bear and hordes will hopefully be kept in check with gratuitous amounts of blast templates.
Raider spam, and the like, will probably cripple the list but otherwise I think it should do well as a balanced force.

All comments are welcome as usual.