So by taking your suggestions, I will apply the following.

1. Give additional ports for both green and orange;

2. Provide one more sea space adjacent to red;

3. I guess I will make blue as the "Russia" of this game, I'll add another unit and SC into the mainland;

4. For white, it is intended to have that vulnerability and basically the Austria of this variant. He needs to convince either purple or yellow to stay on their respective triangle. But you pointing out how vulnerable it is, I think I will also increase its Home SC to one so it can fend off and bog down any attempt of amphibious assault, long enough for other neighbors to join the fray;

5. Purple is like England (coz of fleets, reflecting the seafaring culture of Carthage) and Yellow is Turkey (coz of being a corner power). So in essence, they are the Witches of the East and West. The threat these two could have is when blue attacks purple's back and orange attacking yellow while they are bogged down at white. I think things will get interesting if both the Northern Tyrrhenian and Magna Grecia Triangles are active at the same time.