Sounds like you have a pretty clear plan of where you want to go (also, it seems pretty cool).
Since your plan is to integrate with your DAW pretty much the whole time, you have quite a lot of flexibility and can probably hold off on filling your hp until you have a better sense of how the instrument works for you and your flow. VCV Rack is free and has plenty of modules that can cover your needs. Plus, my understanding is that you can use VCV as a plug-in in Ableton. You're also dealing with a lot of modules I don't have direct experience with, so I'm hesitant to make recommendations of physical modules to get or switch out.
That being said, you certainly wouldn't be doing yourself a disservice if you added some utilities to your rack. Utilities are the plumbing and architecture that make your big modules actually work to their fullest capacity and in the most interesting ways. It's unfortunately also true that it's hard to figure out what utilities you need until you're midway through patching and realize you're missing a specific funtion and can't do the thing you want to do. Again though, since you're integrating with a DAW, I'm hesistant to tell you to buy anything. All of the below functions can be found in VCV, potentially for free, as well.
With all that out of the way, I would suggest more VCAs, perhaps a chainable one like the Intellijel Quad VCA, or a stereo VCA (I have WMD's AXYS crossfader/stereo vca and like it a lot), to allow you to craft your sound. A stereo mixer (I have used the Befaco Stmix) might also help control your various voices. You might want to consider something like Joranalogue's Route 4 or Switch 4, for hands-on routing of signals to different effects modules. Also, I just love sample and hold circuits, so I always suggest them. Additionally, you need modulators. What's the point of having access to all of these sound-warping parameters if you don't have any cv signals to use on them? LFOs are plentiful in the modular world, but there certainly are some standouts. I personnaly use XAOC's Batumi and DivKid's/Instruo's Ochd in pretty much every patch. You'll also want to think about attenuaters/attenuverters to tame the modulators. I have Erogenous Tones Levit8 and it's a huge amount of control in a few hp (I've never needed to fill mine up).
These are just things to consider, though, since as you say this is a DAW-connected project, you really don't need to buy much other than the ES module for connectivity and to get going. If you felt like buying modules, though, utilities, vcas, and lfos are where I'd put my focus.
Hope this is useful, and good luck!