A few questions:
1) Is Kagyu (Mahamudra) the most like Zen, or Nyingma (Dzogchen)? I've heard conflicting views.
2) From among the five main Tibetan schools, which emphasizes shamatha/vipashyana the most? I'm not talking about the tantric idea of shamatha-vipashyana, but rather general Mahayana shamatha-vipashyana. My feeling is that it might be Kagyu. I realize that this largely depends on the teacher, but generally speaking, and especially traditionally, since modern Tibetan Buddhist teachers of all lineages who are teaching in the West seem to be emphasizing it more. I have not seen that it is really emphasized that much in Geluk generally (except theoretically in the Lamrim etc.) and also not really that much in Nyingma. I am curious if Kagyu might be more oriented in this way than the others.
3) Are there any Mahamudra teachings that one can receive without doing Mahamudra ngondro? I have heard about Sutra Mahamudra, etc.
4) Are there any prominent Kagyu teachers who teach higher Mahamudra without requiring the completion of ngondro?
Thanks for any advice.
The short answer to your question is that it all depends on the teacher and the student. There is no one way to teach mahamudra. Shambhala is very big on the practice of shamatha, but they also have a lot of hoops to jump through. Get to know a teacher personally if you want the teacher to treat you as a special case. And don't be in such a rush, practice takes time and effort and there's no shortcut for that.