Hare Krishna Dark Warrior,
Lord Sadashiva is an avatara, you cannot be disrespectful to Lord Shiva. Besides remember, Vaishnavanam yatha sambuh.
This is not sentiment. It is stated right in the Bhagavatam.
Brahma, on the other hand is a jiva. Remember- from Brahma down to the ant? They are all jivas. Shiva tattva is very hard to realize, however. And Shiva is not a jiva. If you are saying Rudra, then you are right. Rudra must leave his body, and therefore is a jiva.
Thank you. I hope I am not sounding offensive.