Asalam u Alaikum. All Praise is due to Allah. Coming to your question, It has been revealed that
Allah created death and life to test you (as to) which of you is best in deed [Al-Mulk, 2]
Since this life is an exam, if everyone was able to talk with Allah, then people would try to get details like someone's personal information, future events etc.
Someone has said that
"If you wonder why you can't hear God's voice during your trials. Remember the teacher is always quiet during the test."
Coming to your next question, Awliya' of Allah are those persons who give priority to obey Allah and His Messenger in different aspects of their lives.
‘Abdullah ibn Mas‘ood (RA) narrated a Hadith that:
“Hasten to Jumu‘ah, for verily Allah will appear to the people of Paradise every Friday when they gather at a sand hill of camphor, and their closeness to Him will be commensurate with the degree to which they hastened to Jumu‘ah in this world.”
الحمد لله أوله وآخره