The drum loop is the easy bit... But if you only have the ONE loop, there isn't anything that will say change a major bassline into a minor or diminished one. And the same (even more so, really) applies to chords. There's nothing realtime will turn a major into a minor or 7th, etc..

The only way this works is if you have a different loop for each chord type, and even that has it's limitations... unlike a MIDI line, an audio loop can't have an upper or lower limit set. It is going to transpose as a whole. So, to be fair, you'll need maybe two or three loops for different pitch wraparound ranges, and possible two or three loop sets at different tempi, to cut down on speed change issues as well.

Apart from drum loops, adding in other Parts in audio format is quite a can of worms. Now I expect an MS owner to chime in and tell you how easy it all ought to be, but before you take their word, ask them to play you something they have done in style mode using audio loops... Then listen to it as it goes through the changes, listen to the basslines as they transpose up and down regardless of pitch, listen to the chords move around in parallel motion, and compare it to how smoothly and musically this is done by MIDI arrangers...