Correct we're trying to improve.
There are several reasons for its implementation
1) Numerous complaints about rebels dying out quickly
2) Mid/Late game is notorious for being a cash abundant state
3) Heirs/Leaders are practically expendable and their squabbles/internal struggles are poorly represented at the moment
4) Holding a vast empire and regions which had an identity is unrealistically easy
5) It adds another element of strategy/realism/intrigue as to what exactly you do with the most important members of your faction- in fact often once a leader died out factions would collapse (Pergamon comes to mind)
(And 6- the historians/faction coordinators approved it obviously)
You can still make your own path (as well the other factions) it will just be a little more difficult as it was in history.
As for the other scripts, it was never intended that any of the script would have problem. We do test things before releasing it into the 'wild' but not always will every single detail be tested/caught and fixed.
Thanks to our industrious team members things have been moving along at a steady pace and any bugs we find ironed out but only with the help of your testing and feedback which is very much appreciated and important.