hey Alyssa - when I follow these instructions, here's what happens/what I see:

The first pull-down menu at the top of this window is the input port. The following pull-down menus (Bass, Piano, Drums etc) are the outputs. The reason that each instrument has its own menu is that you can send different instruments to different ports. Click on the Bass pull-down and choose the IAC bus port (You could have specify the name of the ports in the IAC Driver dialog, but by default there may be a port named "Bus 1"). Then, click on 'Set all ports to this', and press OK.

(NO OPTION FOR IAC)

Midi studio in Audio Studio Setup just shows loading.....

What do I desire?

pipe BIAB-> Arturia synth software - Analog 4 and V Collection for playback
pipe -> BIAB -> Presonus Studio 1 for tracking

Should be pretty straightforward, but I'm not able to line up the dots! My MOTU Ultralite 3 is my midi in/out (once MOTU helps me make that work!!!).... so I can route playback through my Universal Audio Apollo x6 for playback and tracking....

Am I making sense? Please advise and thanks!