will a havoc heli help build skills that would help flying my belt cp? or is it basically just a fun toy for indoors

no and yes.

I have flow the crap out my little Havoc but I have never flown a real chopper. But I would say NO it won't help because they are so simple. Just gas it and if it hits the celling then let off of the throttle a bit.

Well I can at least thank the havoc heli for getting me all interested in this hobby in the first place. But then I went out and bought a 400-size collective pitch helicopter. And let me just say that no amount of reading or flying the havoc heli will get you ready for that kind of experience. The first time you throttle up your new machine, the power will scare you and you wonder what kind of damage those big spinning blades could do if they hit you. The BIGGEST piece of advice for your first time flight with a hobby-grade helicopter boils down to two important things. 1) You will notice just like the havoc heli, when you are throttling it up and it still hasn't left the ground that it seems like it wants to tip over and move over to the left. This is due to the action of the tail rotor. Once you are in the air, it will quit doing this but as you slowly start to lift off the ground, apply some gentle right-stick to compensate. and 2) EVEN MORE IMPORTANT...Tail-in hovering only for beginners. This means that you keep the tail pointed at you at all times while attempting to hover. You will find that if you do this, you will keep your orientation and not make some crazy move that results in your model going the opposite way you intend to. Trust me on this, when attempting to master the most basic skill of hovering, if you get the nose pointed at you, you will loose orientation because the controls are reversed, and you might give an input that makes it come right at you! I was just reading a post from an unlucky fellow on this forum that made this same mistake and caught the blade in his stomach! And of course, only attempt to master learning to hover on a calm windless day, or better yet in a gym. So there you go...remember these two things and you will be leaps and bounds ahead of the average beginner who busts up his RTF helicopter 10 min after taking it out of the box due to a lack of understanding of how to go about it.