Fuse 8 is a 15 amp fuse which supplies power to the following circuits:
Left/Right Vanity Mirror Lamp and Switch (I think these are the mirrors on the sunvisors)
Sliding Door Dome/Courtesy Lamp Switch (does this fuse blow when the door is opened?)
Right Dome/Courtesy Lamp Switch (same question as above)
Glove Box Lamp and Switch
Radio (!!!) do you have an aftermarket radio installed???
Main headLight Switch (feeds the dome/courtesy lamps through the mail light switch when it's in the dome light position)
Instrument Cluster
Based on this, I would verify that the dome lights are not causing the problem by replacing the fuse without opening the doors and then turning the headlight switch to the dome position to turn on the dome/courtesy lights. If the fuse then blows, the problem is in the dome/courtesy light wiring.
If you have an aftermarket radio installed, whomever installed it may not have properly taped/insulated the connections and the short may be due to that.
No, I don't have an aftermarket radio...same one it came with. The only thing that I have ever put it in was a jack for my laptop...it went into the lighter in the back. It's out now and the lighter works (I checked just now...no dimes in it.) But you're right...all the things you listed are out.
I'm sending your info to my husband...have him check it.