While I like maps with channels for CVs (old AKDesert was the best), what I always picture is some squad taking off in Lancs, going into outer space and cruising the channels killing CVs as they come upon them.
You can kill 3 birds with one stone. Make the center an island. That gives CVs access to all countries. And the center island becomes a common battle ground for all 3 countries. And with a little modification, the rivers can be your country borders.
A TT or FT is unavoidable. Every map has a center and it's next to impossible to not wind up with one or the other. What would be "adopted" as a FT on your map is in sectors 9,9 - 10,9 - 10,8. The only way around it is to either put strat there or mix GV, AF and strat in that area.
I know it's a rough layout, but double check your field counts per country.