Hi Ikke1996,
To be honest, I do think you need to get more experience with the Neutron. The more experience you get with it, you will start to feel what you might miss on the Neutron and that might translate into what you might want to consider to look at it in modular. If I may say it like this: "I don't think you are "ripe" (i.e. ready) yet for modular" ;-)
So build up more experience, while doing that you can check things like check your budget, what are you willing to spend on modular (do realise that it can costs several thousands and that's just for the beginning of it). Check the size of your planned modular case, choose a size that can hold for the future too, not that after a few months or something you need another case. So think in terms of at least 2x104 HP (Intellijel 7U case for example) or 3x84 HP cases (Doepfer A-100 for example) as a real minimum, better is to think bigger. Meanwhile still building up experience with the Neutron.
You also can check for yourself how happy are you with components of Neutron like:
Oscillators (VCOs)
LFOs
Envelopes (EGs)
Filters (VCFs)
VCAs
Effects
Utilities
Mixers
Audio input/output interfaces for modular
Etcetera
Check component by component what's important for you? How should it work, what should it give you? You can check the basics with the Neutron, try to create an opinion for yourself with that for each component. Once you got that, you can answer easier your above questions by yourself. Don't get me wrong, it's not that I don't want to help you but the best learning curve is if you are going to figure that out for yourself. That requires experience and with that you can easier build an opinion for yourself what you want from each component and from modular in general.
This might sound dull but it really helps is to read the posts in the Racks part of the forum. Don't read the first few lines but read the entire posts to understand why people give certain advices. Start to read with the post that's called "Why your 6U x 84 generative rig won't work" post, that covers most of the starting issues, after that some other posts in the same section (Racks) of this forum.
Modular is not only about making music with it, it's in the beginning a hell of a job to start reading into it, learning about its components and its basic understandings, then the planning, investigations that are required for that planning. And then, and only then, perhaps then start think about buying a modular case. Not straight away fill it up fully, no keep it about half empty. Start with getting experience with the basic components, build up again more experience, adjust your opinion again on the gained experience and then check again what you might require. It's a long road to go (if you don't want to waste money like hell), but a very nice way to go if you are really into modular.
Oh by the way, and also be prepared to learn from mistakes, that's pretty common in modular too ;-) I mean to make mistakes, as long as you see that positively and take that as a lesson learnt, then that's fine.
I hope this helps a bit for starters and kind regards, Garfield Modular.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads