Hi Sagey. You seem to be on the right track with most of the things you mentioned.
Firstly, I am typing this into abphone with a cracked screen so I can’t really see what I’m writing!
Regarding Plaits vs Rings.
Rings can act just like a stompbox effect if you plug only into the ‘IN’. In my opinion there are alot better stompbox sounds to be had than going ‘only’ through rings. To bring rings alive you will need Modulation. Think of all your guitar modulation pedals. The thing that makes them ‘move’ is the modulation. How often have you thought: i wish it went faster or slower or was a bit less regimented, etc. A modular system breaks the modulation into it’s own sphere which gets much more fun but also more expensive. Also, another modules like a noise source (plaits is good) brings the sound alive. The notes to plaits below also relate to rings.
Plaits will only drone away if you don’t pair it with at least a v/o sequence and a trigger. When i was starting out this was A bit confusing so: v/o is equivalent to which note you choose on your guitar and trigger is when you play the string. As there are many Ways to play a note ie pluck, damp, scratch, hard, soft, etc then you start needing lots of other modules to bring in these nuances.
At a bare minimum most people would add an envelope generator to define the attack and decay of each note. I suggest that you get one that can be modulated (ie: influenced by another factor) so that each note doesn’t sound the same forever. A smoothly moving random source is also a must for mutable modules in my opinion. To change notes you need a sequencer. This is a rabbithole topic. I suggest either korg sq-1 or mutable marbles.
The list ends up going on and on, but from my experience if you dont have at least 2 rows of 84hp then it gets hard to do what you want to the point it becomes a restraint. This is probably not what you want to hear because it ends up getting expensive.
If you haven’t already. You should try out Vcv rack. It is a free, computer based, moDular environment. Most of the mutable modules are free to use there. Omri Cohen has a great youtube channel about vcv rack.
Hope this helps. If you hzave any specific questions I’m happy to help, as I’m sure many others are too.
One last piece of advice. It can be tempting to get lots of small modules. Yes more functionality per HP but usually at the expense of playability.