This could be a tough diagnosis.
I don't think the speed control issue is related.
Once you start the car, does the radio work and continue to work? Best to know when the fuse is blowing. That can help narrow down the issue.
If everything works for a while then once the car is hot....cossibly the cooling fan is bad? Once the car is warm and the fan is commanded to turn on, it's blowing the fuse.
Good luck on the diagnosis.