Namaskaram Swami
Sorry for being rude or if I hurt anyone but these 2 doubts were troubling me for sometime
1) Are Vishnu, Brahma and Shiva or Rudra interchangeable posts as there are many mentions about this like in one scripture it is said that when one recites Lalita Sahasranam for 16 times one becomes Mahesvara capable of destruction, sustenance and creation. There are other references also like in Brahma Vaivarta Purana in Krishna Birth Khand 36.28 Lord Shiva offered the position of Sri Hari to demon. In Shiva Purana and Mahabharata also it is said thar if one can please Lord Shiva he may give the positions of Brahma or Vishnu to anyone. How is this possible ? And are Vishnu and Shiva or Rudra also interchangeable posts and can a jivatma take their position and become them(God)

2) Why is Lord Vishnu and his consort are called internally Tamasik and externally Satwik and Lord Shiva and his consort are called externally Tamasik and internally Satwik in Rudra Samhita of Shiva Purana and Soot Gita of Shiva Dharmottar Purana. Even though it should not be like this.

Swami, pls clarify these doubts
Adiyen