I don't know much about Melty Blood, but I definitely understand the distinction between BnB's being easy and BnB's being the basis of the game. I play Bang, and his BnB's are easy enough to execute, and you can combo into super even most of the time. But Bang's game is definitely not reliant on that BnB, it's based largely off of his pressure game, crossing up the opponent and getting in a couple highs and lows, TK shurikens, throwing in a grab, and eventually getting a knockdown and then mixing them up with high/lows, grabs. His normals are so terrible that throwing out pokes in hopes of getting a BnB is simply not worth it.
As opposed to, who cares wtf they do, I can land a single hit and take 1/3 to 1/2 of their life.
Not even Nu can really get away with that, since if they're playing intelligently against her she's not gonna get good opportunities to land her most dangerous stuff. Her most reliable BnB (5D 5D 4D 4D 236D) isn't all that threatening unless she has 50 heat.
As for SFIV, some of the Links are pretty difficult, but it's really just like playing anything else, I mean it's not like Smash has a buffer system (albeit a few exceptions). I dunno, I came from playing Slayer in Gear, and you're really not getting any combos unless you can link his 2K to 2H, and perhaps just as important, 6K to 2K. Granted, Slayer has such good pokes that you can kind of get away without it, but it just opens up so much more. Oh, and Big Bang Upper is there too <_<;