Really, digger, I'm getting sick of having everything you own or want and having the same problems as well. Anyway, what I had happening is certain lights flickering while others remained steady. Mostly this happened when windy. I noted a wrapping of some kind of electrical tape on what appeared to be a splice on the wire leading from my house to the pole. That tape appeared to have some kind of heat distortion. I also noted that any flickering was from lights on one side of the service box. This meant, as you seem to see, one leg gone flaky. I called the electric company knowing they'd give me a talk about how much it would cost me should the problem be other than at their end. They came out and, low and behold, found the problem just where I suspected. They told me that the wire from the pole to my house was aluminum but was copper on my side. Copper and Aluminum are known to not mix perfectly. They can actually have a diode effect which causes the connection to heat and corrode faster. I guess they just put some sort of new clamp and cleaned it up. No more flickering.
Now if you really want to be brave, you can go outside and beat on your incoming service wire with a big stick while someone watches your lights. Just don't use a length of EMT.