1. When returning to your home base, wouldn't it be logical that a fleet/BG that wants to move into/through an enemy-occupied area, that they would be allowed to "fight' their way through the enemy occupiers ??
2. Should ships that are "doubling up" on enemy ships have their Firepower negatively influenced? It seems that they would be:
a) at a greater range
b) have their gunnery blocked by screening ships
c) have the vision blocked by gunfire smoke
Maybe just a -1 to their Firepower?
Again, I think you are not really looking at the game as an exercise in naval strategy with you as the person responsible for that. Sure, you line ships up and the 'shoot' at each other to resolve combat, but that is just a mechanism to get a battle result and to have fun getting there, not any sort of simulation of actual combat. So, sure, if you want to do something about doubling up, go ahead. But its not really about that, as a game.
For your rise item, though, that is what it is about. The greatest fear in the minds of the commanders of both sides was being caught with major opposing forces between them and their home base. That is why Jellicoe said he was the only man in the Empire that could lose the war in an afternoon. So the players need to be subject to that same fear and consider it in everything they do. The rule about not being able to go back through opposing areas is specifically to produce that historical effect. Sure, you can change it as a house rule, but at that point you are no longer really looking at a strategic game on the topic since it no longer involves the most important aspect in the minds of the two people the players are supposed to represent.
Oh, and sorry to be so long in reply. I am afraid I very seldom come over to BGG.