TL;DR:

I have 26hp left for VCAs, other modulation (EGs), and some effects. What am I missing that you would recommend?
If I get rid of the Plaits (possibly redundant, as well as the 2HP Mix that lets me hear it), then I have 32hp to work with.

Goals, in order:

Single Eurorack case that lets me do drums and a bassline. Maybe one extra voice as a lead, drone, or fx if there's (mixing) room. I like DnB, Techno, Dubstep...
$2k budget. I am WAY over this at ~$2.9k (minus Vult Freak, owned already). I see no other way out. I am going to have to beg the wife for forgiveness.
Integrate with MacBook, for add'l modulation and/or recording multiple voices at once.
Room to expand. I'd love to get a new module every month, not a fan of having to get another case so soon... but I can sell the Caixa in the future, NBD. I'm also a big believer in "constraints breed creativity", so having only 104hp usable is more likely to keep me creative, not less.
Aesthetics. Least important requirement... but an all-black rig looks pretty cool, NGL.

MacBook w Ableton Live 11 Suite and VCV Rack.
Korg SQ-64, Dirtywave M8, and Novation Tracks for external sequencing options.
East Beast. Was originally planning on using this in my first Eurorack, didn't realize how much space it took up, almost no room for anything else already...
Vult Freak. God I love this filter.

Caixa 104. Gorgeous case. I already use the built-in modules for most patches in VCV Rack (except balanced inputs), so this is a great deal.
PPW, Alan and Enigma are for “portable”/“exploration” modes. If I don’t have a laptop hooked up through ES-8, or the new SQ-64, I can still jam. I LOVE Turing Machine (Alan for less HP), that's the only non-negotiable module in this line-up.
I want powerful drums. vpme.de QD sounds amazing. It takes up a huge amount of space though.
Manis Iteritas. I like filthy basslines. The Osiris is an alternative; though it's 2hp wider, I love wavetables.
Plaits (Knit for 6hp). May remove, see Q's below.
Big empty space in the middle is for modulation, see Q's below.
Vult Freak. Can operate as two filters at once. Already own this one, so it's going in.
2hp Mix. This is only for add'l voices like Plaits since the built-in mixer only has two (stereo) channels.
ES-8. Pricey, but I really want to integrate with VCV Rack and this seems to be the best way. (I have a MOTU M4, but it's in a semi-permanent place in my home studio for my monitors and not a portable option.)

How many VCA's would you recommend for 104hp? I don't know what I need for modulation. Looked at a ton of options, see the loose modules below the rack. I currently have the 2 built-in Caixa LFOs, Pamela's, and Turing. Definitely need VCAs, how many would you recommend for 104hp? I need 1+ envelope generators too, and definitely want to duck the bass with a VCA. Maths is super popular, but it takes up a lot of room... but if it'll also let me mix in an additional voice, maybe it makes the most sense. It does too many things for me to remember what it's capable of, without ever having played with one in person.
Should I get rid of plaits? I'd love to have one extra voice, but I already have Manis and QD (and QD is technically 4 voices?), plus the built-in Caixa stereo mixer only has two channels. I threw in the 2hp Mix for this reason but that's another $99 and that's probably too small for performing. Would you chuck it? Removing that and the 2hp Mix frees up 8hp for more modulation space. Or at least future expansion.
Recommended FX unit that would fit too? There are zero effects. In standalone mode w/o MacBook some stereo spread or light reverb would be nice. Maybe a disting? Those are "menu-divey" but I don't see myself playing with that a lot when jammin'.