As the son of a former cabinet minister, yes the permanent secretary is a vital component of cabinet.

As to respect, this is earned, not necessarily demanded. One is to lead by example, earn respect by giving respect and leadership. Young leaders cant demand respect, cant treat people poorly and hope to be treated as a leader. Young leaders have to know that they have to earn the respect of their colleagues, acknowledge the experience of others and be humble enough to learn from them. This is how a younger leader gets respect from others.