I do use Massive, but I also use Reason, here's my chip of advice for you.
I would stay focused on Thor as it has a bit more to offer than Malstrom but it is complex in a way, anyways, Massive honestly requires no knowledge of synthesis.
People like Bobitch make sick sounding basses, and don't study a bit of synthesis(he admits he hasn't).
Learn some FM Synthesis if you really want to know your way around Reason's synths, you can't really achieve FM Synthesis out of Massive. It will really help you as a producer, but if you're like me and are 'too cool' for learning, I would do what I did and teach yourself, learn what EVERY parameter/filter does. If you are looking for a really metallic sounding bass, I would use Thor's FM Pairs as you can tweak them to pretty much get any sound, then try a shaper with any setting but i like peak/unipulse/wrap with the drive up a bit.
Then experiment with Scream on Thor, I like the modulation setting.
Try resampling aswell, the possibilities are ENDLESS.
Well, I hope I helped you a bit.
Cheers
