I am frustrated by a lack of signal domain objects on my raspberry pi. Is this problem surmountable?

I don't know what you are referring to, because I installed pd extended and all the audio object worked, but I couldn't do anything serious because of the little cpu and ram...
so my actual idea is that raspberry pi can be used with pd just to send midi data to an external device or for other data stuff
hoping to be contradicted
cheers

Hey, not a bad idea!