Have you personally been able to get anything to actually work in livespice? I've observed that it's UI is so broken that it's practically unusable

Can you say what's broken about it? Is there something that prevents you from following the tutorial to build the low pass filter?

A lot of people have problems with audio IO (the ecosystem of audio devices, drivers, OSes, etc. unfortunately is a minefield) but I haven't heard many complaints about the UI.

I'd have to open it up again and try to do something with it to remember.. I think it was like I'd drag something onto it, but then I couldn't delete it, and a few other unintuitive things.. and yea, I never could get the audio IO to actually work

Delete should just be the delete key... I think there was also an item on the edit menu to delete the selection. I tried to make it behave as standard as possible (the usual windows shortcut keys for cut/copy/paste/delete/etc.). There's an annoying issue in the GUI framework I used where the right part of the UI has to be in focus for these things to work. Maybe that was the issue.