Hi Glenn,
It is quite hard to see details in every area of the boat. But I think that in regard to questions 1, 2 and 3 there was a turnbuckle in each area; this was necessary to adjust the tension of each cable.
For question 4 I can't think of a wire coming from the two rear cables. But there was a very thin diameter wire in front of the tower. Just like on the VIICs, the IXs had a very thin wire leading from the front jumping wire into a circular insulating conduit at the front of the tower. Do you know the photo of U 190 which has the Canadian sailor standing on the top of the tower holding both a White Ensign flag (above) and the Kriegsmarine flag (below) with his hands? In this photo you can see the thin wire extending from the front of the tower up towards the front jumping wire (it met with the jumping wire ahead of the splitter).
Cheers,
Dougie