In modular, all of the things that you take for granted in a typical synthesizer must be thought out.
Mixers are a must as far as utilities. Simple mixers are great for summing together multiple oscillators or multiple CV signals together. The more complex, audio mixers are great for routing. Both are part of a well balanced set-up.
Generative set-ups aren't beginner friendly (truly generative set-ups). It's something to strive towards... but only after some hands-on experience. Right now, you're shooting in the dark and I don't think generative means what you think it means.
Define "need" as far as a sequencer. :)
Your rack is tiny and you're populating it with large modules like the Vermona and Maths. I would buy a bigger case and leave 1/3rd of it unpopulated. I'd ditch the Vermona and find something smaller and simpler. I'd also ditch the Pico DSP and go for an Expert Sleeper Disting EX... more space... but you'll get more mileage out of it in a small set-up.