Reply to S4 & Maschine on Same PC

I just want to check my understanding of this and if its correct.

If I want to connect my Maschine to my S4 and use both on my PC I would run a midi cable from my Maschine to my S4 and then setup up routing in each piece of software?

Now for the audio. Which I sort of tried out earlier. I've got a Fast Track Pro. So I use that for the audio of my Maschine and connect the output of the FTP to the input of my S4. When I tried this earlier I found the volume was very quiet compared to a track playing in say deck A. I tried adjusting the gain but made no differenct. I've max'd out the volume on the FTP as well. Should I have live input on deck C & D or does that not matter? I currently tried with deck D.