Excellent read so far my friend. Much better written than my Oda Campaign. Imagawa are usually a very tough proposition, they are my favourite clan to play as and I was going to do them in my next campaign but you have beaten me to it lol. If I may make a reccomendation, I would suggest taking Mikawa as soon as possible. Its very easily defensible, away from the dangers of most of the other clans and has a reasonable income from farming. I usually take it immediately and build it up as a fall back position if things don`t go to plan in that part of the map.