Questions and comments:
The Lapsus and the Quadratt do much of the same thing. Why do you have both in this small case?
The Intellijel VCAs do not have any kind of manual control (like a bias knob). I would start out with 2 to 4 VCAs with bias controls. I'd lose the Intellijel VCAs as well as the USB port and put in an Intellijel Noise Tools unit for some Sample & Hold, slew, and noise goodness.
Scales is nice. But if you're okay with not having real time controls, a Disting EX or a Ornaments & Crime Micro will give you quantizer functionality. Plus when not needed for quantizing they can do a lot of other useful stuff. In a small case, getting more out of each module is definitely a huge bonus. Look into both the Disting EX and O&C and see if they are right for you.
I would also get a small stereo mixing module. Budget around 6 to 8 HP for that. The Quadratt can be used as a mixer. But I think of that as secondary, as the attenuverting portion is much more useful, especially with modules that don't have built in attenuverters.
The BIGGEST ISSUE.
Steppy and Mimetic need external clocks to make them function. Where is this clock going to come from? Also, where will you get the reset signal to restart them both in sync? I would put something like a Pamela's New Workout in the case. It also has multiple functions that are very useful.
Final thoughts:
Small cases seem ideal for first cases. But they are not. Larger cases allow for growth and learning. They are much more forgiving WHEN you change your mind or your level of knowledge expands. Also, small cases tend to have depth restrictions. Not all modules fit in shallow cases like a Palette. Be sure to do your homework on EVERYTHING if you really insist on a palette case.