Hi,
Controls are designed for HOTAS, and to fly advanced simulators yous should get one too. Everything will make more sense then. RAZBAM has it's way of making keybinds, that's true, but weapon cycle button will not work in case of M200c because of it's design.
In theory:
To select Magic or Canon you need specific key (one for each) located on HOTAS, and S530 should be selectable via PCA. The thing is, that if you select Magic or Canon, to be able to select S5300 you need to exit previous weapon mode, and I have no idea how to do this.
RAZBAM has made cool and realistic update to weapons system, but provided no documentation at all, so yeah, I have no idea how to operate it too.