You can indeed use VS Code with Mac but it does come with its own… thingies.
First, I would recommend using cmake instead of the projucer. Then you can use the cmake extension in VS Code and it can help set up Intellisense and you can run builds and debugs from the GUI instead of tasks/launch configs. There’s a couple of good links and points in this thread:
The problem is that the way JUCE projects are compiled can throw off VS Code’s intellisense sometimes, so you might have some problems jumping around the codebase and having function argument hints, etc. This is related to:
Notarisation should be unecessary if you’re not distributing your plugin but code signing is mandatory for M1 Macs, even if you just compiled the code you just wrote on that very computer. Luckily cmake will handle this for you without the need for an Apple ID.
I would recommend getting set up with the official example to verify all the parts are working properly before slotting in your own code:
As for DSP… no idea.