I'm considering buying the Vandal kit, primarily for the Graffiti paint; can anyone tell me whether it's useful/worth it? Answer quickly plz thanks

Paints really depends on your playing style; that'll determine what turrents you'll typically come up against. If you want to last as long as possible in a battle, a medium hull would probably be best without drugs, a heavy hull with them.

The Atlas kit is very good at your rank; in a general attack pick one tank and keep on shooting it until it's destroyed or there's an immediate threat to you; then repeat. In CP Atlas can guard points; in CTF it can guard the flag. I haven't really found it efficient for acting as the primary offensive tank unless you all-out drug. When catching gold, the first thing to do is to get to the right spot, preferably 5 or more seconds before the drop. Take out light hulls if possible; do your best to ensure that tanks can't push you in a diagonal or perpendicular direction.

I'd suggest firebird, twins, smoky, or vulcan; those turrents are in my experience the op ones at M2. As for hulls, probably Viking or Titan.

Does anyone know whether the Vandal kit is useful/worth it?

In my opinion either Smoky or Twins; I haven't found hammer M3 to be that good. Twins is superior to smoky in close range combat; however, Smoky is more versatile than Twins due to its much longer range and critical damage. You seem good with Smoky so I suggest that, especially since Twins M3 on a M2 medium isn't going to last long against players around your rank; you're going to attract a lot of fire in a battle with such tankers (unless, of course, you're on a reasonably compatible team). With Smoky you can attack tanks at longer range.

In the long run, would Africa or Lumberjack be generally more useful? Vulcan or Ricochet?

I use Freeze M2+Viking M2+Electra :) . Very effective.

How many times do you get killed per battle?

Won't work in Sandbox CTF

I use VIking m2+Freeze m2+Electra, which is very useful in CTF battles :)

True, totally true. I'm not sure about flag captures though, unless you have a heavy/medium tank.

Freeze m2+Viking m2+Electra :)

^ +1 ... SWAG HAS M2 dictator an M2 rail You probably mean M0 dictator and m0 railgun.

Definitely Dictator :)