Hi farkas
Hi Shakespeare

Thank you both! That's exactly what I came here for.
@farkas: Thanks for your suggestions and updating the modulation sources! Especially the Links and 3xMIA as utilities would have gone by completely. I was always - maybe somehow stupidly - under the impression I also could attenuate the signal with the quad VCA and didn't think of it as a mixer. Finally, I like your way of thinking to 'implement' my guitar into Eurorack. So far I don't have something to convert my instrument signals to line. Any suggestions on your part?

@Shakespeare: A great thought to use effect pedals after the Eurorack! Thank you. But I have my concerns and reservations. First, I would want to be 'independent' from my other gear. That's not to say that I wouldn't joke/jam around with an external drum machine or my guitar. But I might also use my Eurorack outside my house and wouldn't want to take my pedal board with me. Second, it 'just' feels better (I guess) to be able to manipulate everything (effects, in that case) within arm's reach.
But I am truly grateful for your creative approach thinking outside the box ;)