look for me at the seminar, as I plan on going there too!
As to Yamada Sensei; he is a wonderful teacher and sometimes really emphasises the basics over the course of a seminar. He is warm and inviting, and I am sure you will enjoy the seminar (I go to as many of his seminars that I can drive to each year). Don't worry about taking ukemi, as the only time a newer person is likely to get used for ukemi if he (or really most teachers) is demonstrating something for a small group or person, and you get called on with the rest of the group. He will also take care of a beginner, so no need to worry.
Look forward to seeing you on the mat (look for me, short woman, a bit round, with short hair and a big smile).