Okay, I see what you mean. Well, think of it this way. Book knowledge is downloaded, experience would just have to be gained the old fashioned way.
Every culture has a passage into adulthood. America has the 18th birthday. Israel has barmitzvas (hope I spelled that right). African tribes have tests. Now, there are also other rights of passage along the way and some after, but in general those are the main ones.
Due to their nature, I would expect the Vasari to have tests of maturity and judgement.
Let's say that the first four years of their life are free time where they can act like ordinary children as they have not yet gained any knowledge. Upon their 5th year (or other measuring tool of time, but since we don't have one for them, I'm using ours) of life, they become applicable for the first Vexperok (from the latin "experior" meaning test, and from the english "vex" meaning confuse).
This first of the Vexperok would test the basic foundations of social skills. For this test, they are placed inside a chamber and are holographically presented with a few situations. This would be more of a passive test. Each of the holograms has a distinct personality that the young Vasari (or Vasling as I'll be calling them from now on) must interact with. Some characters are belligerent, while others are friendly. By evaluating the Vasling on a predetermined rubric over the course of a few hours, the Vasari proctoring the test may pass or fail the Vasling. If passed, the Vasling is rewarded with a treat of some sort (they are more or less children you know, so some sort of candy would work...). They will also be implanted with basic scientific knowledge at this point. However, if the Vasling fails, it will be strapped down and have a hot iron make a tally mark (or other system of counting) on the left shoulder of the Vasling. It shall be tested again one month later. Should it fail again, another tally will be added, only this time, a more painful system is used.
The second Vexperok would test common sense at the age of 15. This test would be executed the same way the first was. By testing the common sense of the Vasari, the proctor may determine whether or not this Vasling is ready to join the general workforce of the Vasari. If they pass, the Vasling receives knowledge of physics and engineering. If they fail, the same system used above, only on their right shoulder. This is the last stop for the lower class.
The third Vexperok is probably the hardest and tested at age 20 with the intention of checking to see what the Vasarling values most. They will be given 300 images which they must place in order of greatest to least value to them. The "key" is chosen by the Omnipitor as this tests the very foundations of Vasari wisdom. If they succeed, they are given complete knowledge of the inner workings of a Vasari ship.
The fourth and final Vexperok is only for the upper class (would-be council members, captains, admirals, Mani'k, and Omnipitors) and tests endurance at the age of 30. Now we can assume that for something that lives 500 years (they are reptiles which normally live for a long time and have nanites to fix bodily damage), 30 would still be quite young. For this test, they are sent to a remote desert planet and put under a dome with a crashed spacecraft. Using the materials from the ship, they must survive and send an interstellar distress call. After another year, the proctor will arrive to take the Vasling home. If the Vasling fails, they die. Or rather, they fail if they die as there is no definite end to this test regarding a time limit. If they survive, they become a Vasari and have the knowledge implanted in them according to what field they intend to go into.
The Vexperok would test many of the things the Vasari value and would help assure that their system works.
As for your comment about parents... I know you like the alponian idea, but I would think that there are other, more efficient ways to reproduce. Mass cloning works wonders and helps to assure that the Vasari are on an equal playing field for the final Vexperok. However! Class systems only work if you are born into something. Advancing past your original class would be nothing short of a miracle. For this reason, they must be born rather than just created in cloning chambers or transformed from something else.
Also, no offense to you, and I know you love the idea, which is by the way creative, but I find a few problems with alponians.
1. Viral therapy would be a whole lot more efficient than covering someone in slugs.
2. The Vasari ruled their slaves from orbit. They never went down to the ground as they considered the other races beneath them. To allow someone to become one of your own requires you to first think of them as an equal. The Vasari are incapable of this.
3. No class system works without having been born into one. Your idea is that every Vasari starts as something else. Well, originally there would have had to have been actual Vasari that reproduced sexually or asexually. They would have made the class barrier impenetrable by nothing short of a prodigy. This flies in the face of something that is based upon everyone starting at the bottom.
I understand you want the Vasari to be barbaric sorts of things that act like the borg in that they absorb all others, but realistically, they would have to be somewhat democratic and peaceful race in order to survive for so long while on the run. They fight because they are desperate, not because they want to.
You can continue down the path you have for sinners, but for the benefit of future fan-fics, I want accuracy. I mean no offense to you here, but I'm just saying that I find that the Vasari would have to reproduce the old fashioned way in order to use the system they do. Sinners is a wonderful story that you have created and I want you to continue. Its just that for those who come after you, they can look at your example and this thread and see what to incorporate. This thread is dedicated to what would really work for them, not what sounds cool in a book. Once again, you have done a wonderful job in Sinners, its just that I don't really think the Alponians would work...
I'll say it one more time. I'm not trying to be mean or be offensive, I'm just going by what would logically work. If you can explain the alponians, then that's great. Its just that for now, they seem to be somewhat pointless unless you were really short on crewmen for your new capital ship. I guess it would have a purpose there, but ehh... I'm done...