There's quite a bit wrong here...first of all, if you're using a powered rack, have you confirmed that it can handle the 5V rail current draw from that Metasonix module? If not, you'd either have to employ a Metasonix (or another similarly hefty) power supply that can handle the tube filament current draw, because a lot of basic Eurorack supplies cannot deal with the operating current draw, to say nothing of the much shorter but potentially greater startup inrush draw.
Second: the Neutron...does not appear to actually exist yet. Sweetwater, for example, doesn't even list it...and they had an advance listing for the Model D for way over a year prior to when Uli finally got around to (likely not getting his ass sued by Moog and) getting them on the shelves. In contrast to the Metasonix powering issue, I don't think any Eurorack power setups are capable of powering up a fictional device.
Third: there's several discontinued modules in here, one of which has already been superceded by its manufacturer (Braids; now Plaits).
Last: if part of the plan is to use some of this as an 'insert' in Cubase paths, there's another way to do this...let's pull out the monkey wrenches...
OK...now this makes more sense! (Or rather, it would make more sense if MG's forum had actually linked the right image instead of the empty case. If that's still showing here, click the case and the correct image should pop up!)
To start with, the ES-8 can handle either audio I/O via USB or ADAT input to provide CVs via Silent Way. That cut a lot of stuff back really quick! I then added a quad wavetable module which also can handle MIDI and does 4-voice polyphony for that 80s-ish Thomas Dolby sort of thing, plus a Quad VCO for audio sources or stacking as one honkin' big single VCO. Ring mod via a uMod, then an 8 channel mixer that can either configure as 8-1 or 4-2.
Processing provides a waveshaper for distortion/folding, Doepfer's version of a 'wave animator' to get that sweepy sawtooth sound, sort of akin to the Roland 'Supersaw', then your Jove JP-6 clone filter, plus a clone of the ARP 2600 'pre-lawsuit' LPF...both of which also have dual inputs for further mixing purposes.
Bottom row: passive mult (you probably won't need a buffered one with this setup), noise, S&H, and random modules with Doepfer's clone of the Buchla 'Source of Uncertainty'. Then modulators: Batumi, Maths, and a Quad ADSR. Veils handles some mixing as well as the ability to shear off a VCA or two for CV amplitude. The neat little Ginko Sampleslicer handles your sample-manipulation, Warps for more processing and the 20-band vocoder. Stereo mix via the 4-in Doepfer stereo mix, plus the Happy Nerding output has a second parallel stereo in to allow you to take a second audio path out via that same balanced stereo pair.
This should fit all of the functions you mentioned above, and fits in an Erica 2 x 126hp cab. The total came out to about $5200...but that would be in USA pricing, and since I used a lot of stuff here that tends to cost considerably less in the EU, we even seem to be fairly close to your 4k EUR budget constraint! Flows better, works better, no power surprises (the Erica 126 case [NOT the skiff!] has a very beefy linear power supply for very quiet and ample DC), and no fictional devices! Works loads better, I think!