@Nabroc I had a minute so I took your original rack as a starting point and made some adjustments:
Notes:
1) I don't believe the Mantis has a 1U row, so I removed that, but much of what you had there I replaced in other utilities.
2) The Ginko looks like a sick module, but I'm wondering if you have to code with it? Either way I might nab one.
3) I replaced the Erica Synths clock module with a PNW (which is really fantastic).
4) Kept the Ladik LFO, it looks sweet.
5) I added a micro Rings since you mentioned wanting plucks and strings and it's a really great Euro module.
6) Swapped in a Maths plus an Intellijel Quad VCA, Maths is great, can do EG and LFOs for you as well as attenuation/attenuversion.
7) Added an FX Aid since FX in the rack go a long way.
8) Added in a Happy Nerding Stereo Mixer as it's reasonable priced, three channels should be good, and it also has a headphone out so you won't need another module.
This comes in a good bit more expensive than what you'd posted, and I'm definitely using a few popular modules here, but I think it'd be a good starting point for exploration and that empty row at the bottom will give you lots of room to expand as you learn.
my tunes: https://stevehand.bandcamp.com/