Fuses can be bad even when they look ok. So, I replace fuses by switching two identical fuses to see if that's the problem. Often, it is. Then I just replace the defective fuse.
In your case, you may have to buy a box of fuses and replace several at a time, until you've gone through all those in the panel. You'll want to have a bunch of spare fuses anyway, so you're not wasting money.
Your rig is 9 years old, and problems with a bad ground wouldn't normally occur until later, unless your rig was exposed to high humidity, flooding, salt, or whatever. However, with older rigs it is a very common cause of electrical problems.