Hi Dennis-
 
I think that part of the confusion you have stems from the understanding of the word eternal.    Since the authors of the Bible thought in segments of time- "age or ages"- the world eternal appears in scripture to represent that concept.  Of course in modern English the term eternal has other connotations so you can see the confusion.  Another Author and acquaintance of Arlen Chitwood was the late Gary Whipple.  Although Chitwood does no follow all of his thinking, your reading of the book "Shock and Surprise beyond the rapture"
by Gary Whipple might help you see that the eternal loss of the life of the soul is speaking of either an age or ages depending on the degree of rebuke.  It refers to the setting aside of an individual during the duration of a period thereby allowing no involvement in the present focus of things.  This age of 1000 year reign of Christ has a beginning and end and a Christian can have an intimate experience with the workings of things during this time, or they can forfeit that part of their inheritance through neglect like Esau of the O.T.
                                                            
  There will be christians that are saved, yet so by fire, but also find themselves on the outside of the functions being carried out to complete God's plan for man.  This plan will continue during 1000 year reign of Christ and will not be completed until the new earth and new heaven are brought into existence.  I had a discussion with my boys over this and likened it to their involvement on the football team.  Those that are anticipating action on the field,game day, will be those that paid attention to their coach, practiced the drills, ran the plays in the manner the coach designed and developed good team mate skills.  They also had to develop skills that would come naturally out on the field.  Only the correct attitude and the practice of listening to the coach could produce these essentials.  In our race of faith, the coach is the Holy Spirit.  He knows our "design" and knows how to bring that to its best.  He works at trying to guide and direct us our whole life, but if we do not have the ears to hear nor the attitude to follow, then our time in heaven will not be on the playing field but on the bench.  Or you might not even make it to the bench but could find yourself tossed out of the game and in the stands watching those who did make the practice time a priority.  That doesn't mean you are not at the game-"in heaven" it just means you are not allowed to participate and in that sense you are suffering a loss.
 
I know you might think that I am making things to simplistic.  I am a mother with children to guide and simplistic is how I have learned to share with them.  What I have written comes from years of questions and gleaning from the word.  If you are really interested in pondering this subject, then I again urge you to read Shock and Surprise Beyond the Rapture by Gary Whipple.  Once again there are parts that I am still pondering over, but it will hopefully answer a few questions and probably provoke more.