Well you’d want an active blender at the end.

Also, you can’t really do analog detune.

Best you can do is chorus.

yup, that.. they should (in theory) ‘push’ the signal where you want it to go.. I don’t know enough about these things to be honest, but I’m thinking exactly what your dad is thinking.

…. most signal splitters/mixers use an active system using buffers/line drivers to route the signal in multiple directions and blend them back together, doing this passively buy just splitting the signal and trying to join it back together doesn’t usually work very well… that’s all i’m saying. I don’t know know enough to even begin to suggest how and where you should incorporate this into your design though..

If you wire two signals together and put them to an output, it generally doesn’t work, but adding a small amount of resistance to each signal is a quick way to get it to.

100kA means 100k ohms Audio taper. Volume works on a logarithmic scale instead of a linear scale, so audio pots are designed to give you a smooth taper in volume with audio signals.