Most SDRs are RX only so there's zero need for a license for them. As for the other points, the Technician license is super easy and you can pass it with minima

Most SDRs are RX only so there's zero need for a license for them. As for the other points, the Technician license is super easy and you can pass it with minimal study. If you can't pass the Technician exam, you'd actually be hard pressed to meaninvcully participate in those activities you listed. If you don't know the regulations around operating a repeater how are you going to operate a repeater? If you don't understand just a little about radio propagation how are you going to actually do any DXing or communicate with space hardware? Ham licenses exist because radio transmissions affect other people and not just yourself. If you don't know what you're doing to can keep me, your neighbor, from participating in the hobby because your TX power is too high or your antenna is just an untuned jamming device.