Ianis: 1) the "parry" button should be clicked at the right time to parry an incoming blow , currently you can hold the "parry" button and block everything which is arcadish
Holding up a block and waiting for an opponent to hit straight into your block is indeed extremely silly from a real sword fighting viewpoint, but at the same time I think making combat even more dynamic than it already is will also make it unplayable.
What could be really cool, and right up CDPR's alley, while making combat a lot less clicky, is if the game handled the attacks and parries for you, continuing to fight and block intelligently even when you don't do anything, and as a player you only get to make the strategic decisions: who to attack, how much priority you give to blocking over attacking, speed over damage, etc. And then the game uses that info to determine whether to block/counter/sidestep an incoming attack.
You could put a lot of real fencing moves into that. Program several different counters for several different kind of strikes, each with a certain cost in time, stamina and defense, possibly dependent on various external factors too. Done well, it could make combat really realistic, beautiful, and different every time.
2) you should be able to "thrust " an opponent and leave the sword stuck in his body ( by holding the "strong attack" button ) this way the enemy would bleed to death with a sword stuck in his belly (and geralt would draw his second sword ) , would be awesome
Looks cool, but is only really a smart move if it's impossible or dangerous to retrieve your sword. I believe you bleed faster if you pull the sword out. Though the sword would still hinder the guy stuck with it, of course.
4) silver sword should break or bend when used against shield or humans with steel armour and it should be possible to "disarm" an opponent during a fight (and be disarmed ) , making him lose his sword in hand after a series of 3 successful parries for instance
5) bleeding must be more fatal , pommel attack with European sword designs should be possible at close range (say for instance : hold "light attack" and "strong attack" at the same time to produce pommel hit )
6) you should be able to perform a few "unarmed " wrestling stuff like any medieval swordsman could , i mean sort of ju-jutsu projections when at close range or after having "disarmed" an opponent or if you got disarmed yourself
Ringen am Schwert (wrestling with sword) would be amazingly cool. Go from a parry to an arm lock, throw, disarm, punch, etc.
Though if you go that way, it might also be cool to include half-swording techniques.
But if you want the player to control all these combat options in detail, you're really looking at a very detailed Streetfighter/Mortal Kombat style fighting game, I think (I have no experience with any of those, mind you). But for an RPG, it would be cool if your character could apply these techniques automatically, and you get to decide which to focus on.