1st of all.
You have more than enough basic marine squads.
In the main rule book, it states the min required troop choices is 2. You have 2 troop choices, and that's all you ever need for any pt value.
2nd.
You definately need a daemon prince. Currently, a winged slaanesh prince with lash of submission is the best choice.
3rd, since Special characters got better, get either kharne the betrayer, or abbadon depending on preferance.
4th. Definately get a greator Daemon. 100pt for a greator daemon is a steal.
5th. You could get some anti-tank with chaos havocs with 4 autocannons.
6th. Drop the rhino, rhinos have become coffins of death ever since the 4th edition rules came out.
Death guard and berserkers are both good troop choices, but you don't need max squad sizes. When given the choice, always stick with min-squad sizes of 5.
So, my advice is basically to minimize troop choices. And spend most of your pts on HQ choices, some anti-tank havocs with autocannons, and possible some fast attack, like raptors. And avoid death coffins like the rhino.
Also avoid getting vehicles in general. If your army doesn't have a single vehicle. All specific anti-vehicle weapons that your enemy picked like haywire grenades will be completely useless.
