Again Winman you lump one Gap theories view of the casting down into a pot and say all those who believe in a Biblical Gap believe this.
The Casting down of Satan is two part like other doctrines of the Bible (i.e. the visitation of the Lord, the chastisement of Israel and others). He was indeed cast down from his position in heaven as anointed Cherub (as far as the duties of that position go) he may still claim the Title. his access to heaven is limited today to only being able to accuse the brethren. he has no general access as to mingle with the Holy angles of God on a daily basis. we believe his current home is actually our outer space or deep space. to which he will be cast down from 2 nd heaven during the 7 years Tribulation to face his maker.
Go to David Regan's site and read is anti-gap and gap study. he has done a great job of putting it together and I will borrow from some of his understanding to help in the final formulation of the Non-evolutionary Gap view.
http://www.learnthebible.org/search/node/gap