There are some good tutorials on how to make dubstep bass with massive on youtube, i suggest you watch some, then tweak that sound to make it more the way you want it. Search something like massive dubstep wobble or massive dubstep bass.
There are also some about how dubstep songs are structured. Search for dubstep song structure etc.
Also i suggest layering the bass sounds. Like create 2-4 different ones that play the same thing(you can also take some of the layers out at some spots to create more variation). For example last time when i made some wobbles, i first created some wobble tone with massive. Played a melody on it via midi and put the lfo and some other effects(on massive, i think i had filter, resonance and something else, what you want to use depends on what you want to accomplish, but lfo is pretty mandatory, lfo dry/wet control is another one you could automate) on some midi faders, played/recorded in the lfo and other effects live with the faders tweaking the recorded midi melody. Basically i just made some lfo etc changes to a midi loop playing like 1-2 mins, then cut out the parts that i liked and organized them. Then i created a few duplicates of the track. Tweaked the individual tracks sounds on massive(dont touch lfo or what ever else you recorded), so that i basically had a two mid layers, bass layer and one high layer(you dont have to do that exact thing, it depends on what you are looking for). Then i ran the bass and one mid layer through different instances of bias fx(yep, a guitar amp sim, it can do wonders on dirty basses), for bass layer i used some bass amp sim and mid layer some guitar sim(the idea here is not to get super full bass, but basically some dirty bass to give the sound some balls), i used relatively heavy distortion on both. I dont remember what i did to the high layer, but some stereo chorus and stereo reverb sound good on that sort of stuff. DO NOT use reverb on low sounds or low mids(except maybe just a little, basically more low you go, more you want it to be mono and without reverb), it will make stuff sound muddy. Then i sampled some heavy down tuned guitar riff and played it along with the wobbles(and tried to blend it in so that it almost sounds like it comes from the same thing) to give it some support and variation of the sound. You can also use some stereo widener, or well you should use one on the highs if you want to make the wobbles sound really big. Again with the stereo widener, widen more on highs, less on mids and none on lows.
When it comes to drums, you want a tight kick(like short in your face kinda kick, not some long one characteristic of trap etc, it will make stuff sound muddy and with the wobbles and all, its not going to come through the mix well anyways), while snare doesent have to be all that much in your face.
One tip on the part that come before drop, like rising onto it. Take some sound that starts with some strong sound and then slowly fades away, then reverse it. Also use some sound effects on that part where the volume starts from 0 and raises up to the climax, not everything needs to be heard clearly in the mix. Something like a helicopter sound might sound really nice if its hiding in the mix, just adding a bit of character to the sound(<- this type of stuff can be extremely powerful, even if its something really small that you cant even hear properly). And ofc you can put some extra kicks on the riser to make it really come through. You want people to know that okay this is where the drop will come. Going too suddenly from a slower part to a drop will sound bad, so pay attention on the build up before drop.
What come to scales, well minor scales work usually better than major scales if you want to make darker stuff. Diminished scales are also good(i used either A dim or C dim on the track i made, which btw are same notes, but start at different points). Feel free to try other scales too, but minor scales are most common for darker stuff.
Im not an expert on dubstep, i basically just watched some tutorials on song structure and how to make massive wobble. Heres a dubstep track i made a while ago(it has bit too much reverb on the lows, i should fix it at some point to make it sound a bit tighter):
https://soundcloud.com/2mess/pushi27 What i explained on layering stuff, i used on the track.
Im not into making some video lessons etc, but i have been using ableton for quite a while(havent used massive a lot), so if you have some questions, feel free to ask. Hopefully this post gave you some new info :)
I understand a lot of that or at least recognize the tools you're talking about... but still a bit over my head. I'll have to refer back to this in a few days of following youtube vids! Thanks for taking the time to write that out!
Maybe you'd consider using skype's viewer to talk and view my desktop while helping me make a song? I'd happily pay for your time in FG's. Let me know if that's anything you'd be interested in.