I'm still trying to figure how it's broken. Please continue.

Here are a few broken mechanics off the top of my head.  I actually have a muuuuch lengthier and detailed breakdown of the borked parts of the game, but this'll have to do for now. 

1 - You have absolutely no control over your movements in battle.  this wouldn't bother me except for the fact that many battles rely on movement-placement strategies and being in the wrong place at the wrong time can and will hurt you.  You have no control, therefore no ability to avoid this fate should the AI chose it. 

2 - The Paradigm shift animations resulted in exposure to enemy attack with no ability to defend or even prepare a counter.   This wouldn't  be an issue if not for the fact that the enemy ATB bars continue to fill and they continue to attack you when your bars are frozen and are incapable of doing any action or moving.  Simply having the battle stop for that split second while you change paradigms would have fixed this, but instead it's a broken mechanic that most certainly should have been fixed. 

3 - Too much reliance on random chance.  Much of the summon/eidolon battles (it's been a while, I don't remember what they were called) required that you fulfil a certain task to complete.  my friend would do it with ease, and complete it first try.  I would do the exact same thing and fail a dozen times.  sometimes the bar would fill faster than others in spite of our stats, move lists, and abilities all being identical.  

4 - Random weapon/accessory upgrade system.  I understand that there's apparently a method to its madness, but after 60 hours of playing this game, as well as looking at countless faq's and testing for myself, I saw no patterns and what worked one time wouldn't work another time.   Too much reliance on random chance and too little explanation to give you a hint. 

5 - Unavoidable instant kill attacks.  I know there are items to prevent these attacks somewhere in the game, but I didn't get them.  your ability to survive should NOT be entirely reliant on chance (did you find the item?  did you equip it? did you even know it was an issue?).  the final boss had a move that would kill one of your members in one hit.  It was 100% effective unless you had a certain item equipped and had a 1/3 chance of hitting your leader, resulting in a game over.  it wouldn't be so bad except he waits until I think his second or third stage (after 15-20 minutes of battle) to do it, then he does it almost constantly and of all the FAQ's I read, I found no defense against it that I had at my disposal.  

6 - To make it worse, a lot of enemies had attacks like this.  the game literally demands you either be clairvoyant or persistent (keep playing and dying to learn the boss's patterns).  Many bosses and even some regular enemies would change stances or attack relentlessly without any foreseeable warning, often instantly killing you.  Yeah, sometimes they give a warning, such as flashing lights or a stance change, but you have to know exactly when something's about to happen and how to counter it or you will die, and reacting often isn't enough due to the fact that attack patterns change so quickly you're dead before your paradigm shift animation is complete.  This happens entirely too honest, and unless you're psychic and fast, you will die.  a lot. 

7 - Above all else, you die a lot.  In fact one could argue that a game mechanic is trial and error by death.  there's no way a reasonable person could beat 90% of this game without dozens of needless deaths, and that is a flawed mechanic in an RPG.  sure, if you wanna reserve these instakill moves for hidden bosses or hunts, then by all means go wild.  Some of the world's best hidden secrets had to be found during trial and error, but when almost every battle has a combination of random chance and trial and error like that, it's a flaw. This could have easily been fixed by tweaking the damage the enemies did or how much health you had or even making it so you had more warning or you didn't instantly get game over when your one character died.  

A lot of these flaws in the combat system could be fixed easily.  a tweak here, a few lines of programming there.  Instead we have a battle system that doesn't actually work.  I mean sure, people can beat the game,  but you shouldn't need to do the virtual equivalent of shooting in the dark over and over again waiting for random chance to not fuck you up.  as it stands the battle system is broken, and since it would require so little to fix it and make it more balanced, I'm convinced they developers did it this way intentionally, so that angers me.  

To me, a battle system like this would be like playing fallout three and there was say a 1 in 100 chance a bullet would backfire and instantly kill you, or like if you were playing mario and some mystery blocks exploded, sending you back to the beginning of the level. 

4. There are patterns... You just have to find them, probably by trial and error. But it should be pretty easy to find that organic components increase the exp multiplier but don't give much exp while more advanced components lower the exp multiplier but give tons of exp. It's not as bad as you make it sound but this is something that should definitely be better.

5. I've played the final battle two times without any accessories to protect against death, and I haven't had my party leader killed once by it. In fact, I could probably count the times the death strike killed someone with my fingers (from one hand, mind you). It's an issue but not as big as you say it is.

6. I didn't have a problem with this very often. There were a couple of enemies that had particularly powerful moves but overall, pretty much none of them were unavoidable. There are battles you know you have to be prepared for anything and in such battles, you should always be ready to switch to a defensive/restorative paradigm until you know what to expect. That way, I never had too much trouble with anything.

7. Have we played the same game? Most battles had the chance to turn ugly if I wasn't careful but you can prevent almost all deaths simply by being careful.

Personally I enjoyed how any battle could turn bad, how every encounter could be deadly and how careful I had to be at times. Too often I play games where I have no trouble unless I go completely reckless or where there are only a few boss fights that give me any trouble. It was refreshing to actually die because of my own mistakes.

Your Fallout/Mario examples are totally random. FFXIII doesn't have such moments.

It depends on what you mean by taste. Is having over a 100 rpg's considered taste? I have every atlus rpg released on ps3 and ps2. 

Hell yeah I'll be getting FF XIII-2

Hell yeah I'll be getting FF XIII-2

I'll wait for reviews and people's opinion. If it's decent I'll get it after a pricecut.

Oh yes, it is considered taste ^^

Nicely done.

FFXIII is the worst piece of sh*t game I have played this gen when it comes to RPG's wich means I don't have any expectation at all for this one so I might get it after a few weeks when there are user reviews out there

I played the game with a group of 5 people, including myself.  We are all seasoned RPG veterans, and we all had considerable difficulty dealing with this game's battle system.  All of us complained about the same things, we all had issues with paradigm shifting, we all complained that the summon battles were broken, and we all had the end boss kill us multiple times.  I'm not saying it speaks for everyone (we're only 5 people), but when you find a game where your whole RPG crew agrees is shit for the same reasons (5 people who are seasons RPG veterans, I must remind you), then I think it may very well be shit. 

In the last couple generations I've seen gaming go downhill. Not in the "baww, developers aren't creative anymore!" way (though that's becoming more of an issue), but in the way that consumers are getting more and more lax with their standards.  a game with broken mechanics or cheap difficulty or shitty controls tends to not be criticised for this because people are willing to put up with the frustration and cheapness to complete the game, or get the story, or power through to say they beat it.  I dunno, maybe it has really good parts?  All I know is that this form of media is called "gaming", last I checked the "gameplay" section should be the most important.  That is why I refuse to play games that fail at this most basic and most important category.  

But I repeat, I do think that with some tweaks the game could be good, the same way Call of Duty would be great if they changed it so that you didn't instantly die from an unseen assailant in some missions.  I still won't much care for it (I actually didn't like the combat system, but that's a matter of preference not criticism), but if they fix it, I will deem it playable in my eyes and I will be content continuing to support the company.