I feel for you...I myself have left a dojo due to changes in direction, and it can be very emotional and difficult for all involved. The best thing you can do in those situations is to keep a cool head, be polite, and when it's time to go...go.
As for your new training, Yoshinkan is a great organization, and I really like the training there. Personally, I would recommend just training in the Yoshinkan for a period of time and learning the requirements up to shodan. From what you've said of your experience, that should take about 1 to 2 years tops (maybe even less), and shouldn't be a major issue. But I think going through the curriculum is very important, especially in the Yoshinkan, especially if you want to teach. The Yoshinkan has a very specific teaching methodology and curriculum to promote the use of strong basic movements in waza, forward focus, and other things. This generally means that anywhere you go, you can be recognized for the skill that you have pretty easily. Skipping out on that would be a mistake, in my opinion.
I should also mention that Block Shihan is 6th dan in the Yoshinkan. His other ranking comes from the World Kobudo Federation. You can find out more about his training and teaching from his web page : http://www.chudokai.com/index.htm