My wife and I both are using pens that I made 13 and 10 years ago respectively. Last year, I disassembled them and re-polished them - no new CA just the old, as I wanted to polish the scratches out from the years of use. They look well and are not cloudy. I think this (longevity of CA finish) is more subjective than objective. I have been making my pens (and many others have/do also) with a thicker build up of CA (measure every pen and CA thickness buildup with calipers) than just applying a certain amount of layers of CA. Some people apply a certain amount of layers of CA which is subjective, and others apply CA for the thickness build up by measuring with calipers, which is more objective - and scientific for future engineers. :wink:
AS to gluing with the tubes, Some use thin CA, some medium, some thick. After a few blowouts, I moved on to epoxy, but epoxy can do the same. This is an issue in turning (blowout) more than longevity - because as much as we can see physically, blowouts usually reveal how much the epoxy or CA really adhered between the tubes and blank. in some cases it is a lack of adhesion (tubes were oily or wood was oily) but most cases it is the air trapped as the tubes are inserted into the blanks. This happens FAR more than one would think.
This issue of glue adhering to the tube and blank is solved by using expanding polyurethane glues. Full adhesion from end to end. Care must be taken by taping the tubes into the blanks after applying the poly glue - OR the poly glue, in its expansion can push the tubes out, rendering the blank and tube useless.
Until one has had two or three beautiful or rare blanks blow out, CA and epoxy are considered just fine. After that, . . . poly glue.