Upgrading to Mavericks with problematic Aperture Lib

Question

I have a 30K image DB (referenced), which I repair often and rebuild as needed, but errors persist.  I am now exporting major chunks as new "sublibs", but it will take months to repair.  I'm reimporting all images (at least on all the older projects) and reapplying adjustments, all very laborious, but this is the only way I have found to expose and eliminate specific problems. 
I would like to upgrade to Mavericks, but if I need to have a clean lib first, as advice on this forum seems to indicate, then that would be a long way off for me.  Plus, I don't think I can ever be sure I have completely rid myself of errors.
So the questions are: is the new version of Aperture completely unable to deal with old problems?  Must I do all corrective work first?  What if there are errors when I try to upgrade?  What is my best strategy?
My lib includes projects from old iPhoto events (some imports are recent, though I no longer use iPhoto since 2010) as well as direct imports, since I started using Ap3 Beta in early 2010.  I'm finding many errors in these older parts, but a few show up more recently as well.  I have twice had to replace my external HDD due to gradual degredation, so that is the likely source of some of the problems.

Answer 1

The library (~100GB) is on the internal HDD, but the masters (~1TB) are on an external HDD. (I'm not sure this answers your question.)
Note: In earlier years, I used a third party utility to extract some events from the iPhoto lib, but recently I have only used the built-in functionality.
As to recurring errors, my opinion is that there are errors that cannot be detected, or else they cannot be repaired, by the repair utility.
One example is that there seem to be "covert" items. At least some of these apparently are photos that I deleted long ago, but that were not completely expelled. A clue to this are some old keywords that appear in the Keywords list, and may or may not show non-zero counts. These items cannot be found by filtering, so they cannot be tracked down.  I have found some of these items by creating a new project and moving all selected images from the old to the new project, then deleting the old project. The total item count will change and there may be things in Trash, which cannot be viewed but can be deleted. I have sometimes found errors, by accident, by changing the filter settings in a new way (this is very rare, and make no obvious sense).
Another example is that trash often shows up after I export groups of projects as new libraries, then I delete the old projects from the main lib.  And, I'm finding many of these "ghosts" in the new lib; these have no links to reference files, though they are not managed.  So far, repairing the new libs seems to be effective (fingers are crossed).
Another example is that there are many images that I haven't touched in several years, and may have Upgrade buttons on some adjustments. On some of these photos subsequent adjustment fails (expecially curves). Reimporting the photo is the only cure for these.  In many cases applying the same adjustments to the reimported photos have a different effect.