1. When ever any process is planned then it has three phases ; beginning-intermediate-ending . How the beginning happens on that basis it's success depends to some extent . So the muhurtha plays important role in all the processes. When the process is planned means there is some purpose to plan those constituents in specific manner. In that accordance the person gets it's fruit.
From person to person the process and the constituents may differ though the aim or desire of the fruit may be same . This is termed as personalised Tantra . So even the muhurtha for each person may vary as per his own constitution.
2. In these tantras there are three types -same as in Shastra as physical phenomenal-psychological-spiritual. For example the the philosophy of Kashmiri Shaivism is considered as the spiritual Tantra. Shaktipat Yog Rahasya is termed as spiritual Tantra .
In psychological Tantra there are two types -one in which the emergence of the positive energy happens through the d