My post is to shed some thoughts on catholic elective monarchy system. As such, I am not going to spend time to discuss the "gamey" problem. This is just to tell you about one of my many experiences with CK2. If you find this interesting and have not tried it before, do it. If you are so experienced, well share your experience... or suck it up.
Anyhow, to those who had constructively criticized, thank you!
I agree this system is pretty flawfull. The following situation in the same game above explains: Poland third ruler is a lustful sinner, so as the result, relationship with bishops dropped like an inflated balloons. The country had to sit through roughly 14yr of short reign, doing nothing. Poland's war capacity is reduced to fluctuating 20-21k vassal levy, and income drops to 40-50g. The worst part? Nearly 5000g spent and 6 Popes had to be assassnated before a "fit" Pope takes the throne. Only then can the country keeps moving, turning the tide of the current wars.
Truely, elective monarchy with only bishoprics is the best for realm stability (I have a few counts, but because they are all gavelkind (CA now is medium), so I dont care 'bout them). At the same time, it's the worst for religious gameplay.
In the same game I mentioned, HRE is also elective monarchy, but somehow had passed absolute authority. Yet, no "lower authority" war has been fought in HRE (that's pretty sick.) Also, because I only fight excommunicated war against catholic rulers, HRE is left uncheck; and as the result, Poland is having a super gigantic grey blob (original HRE + 90% Hispania) with nearly 200k levy as its neighbor.
So my conclusion is: elective monarchy is far too stable. It has downsides, but it's far too stable.
And my question is: why hasnt HRE broken? It's elective, it's absolute, it's HUGE. Poland experienced regressing periods now and then when sinned king and holy pope take the thrones, but HRE seems to blob ever bigger. I have watched stacks (PLURAL!) of 50k steam-rolling the muslims continuously to the point that I now have to marry my daughters to muslim rulers to assist them against HRE. That's, imo, little too much for a religious game.