The more I play this game, the more I get convinced that at least 90% of what was written in the first post is just whining from a soar cry baby who is still incapable of getting a grip on this game.
Gameplay in general: is sooooooo different from PES 2011. It's still not perfect of course, but it has considerable improvements since 2011. Players are more dynamic and move much more intelligently.
I fail to understand who can someone even argue about one of the areas that improved the most.
Passing and and player control: I also have experienced some misplaced and mispowered passes, and this I have to admit is one of the downsides of the game. Though when I removed PASS ASSISTANCE I found out that this problem can be diminished.
Of course, the counterpart is that one have to master the game with no pass assistance which makes the game a bit more difficult. But once you master it, the game really turns even more interesting and rewarding.
I don't use Player control (I really don't need it), so I won't comment on that.
As for the weak shots, just use Jenkey's Gameplay Tool.
Defence: you have to remember that the CPU will not do (and rly doesn't have to do) the work for the human player, it's the human player who has to 'trigger' the CPU to do the right things. Of course, if you just lay down waiting for the CPU to make some crucial defensive decisions for you (like when to hold a position/line, hold tight), you'll never be succesfull and will always think that there's something wrong with the game, when actually the fact that you don't know how to defend is the real problem.
Problem is, you really don't know how to make this right... well, you simply don't know how to defend in PES 2012.
As for strong defenders getting knocked over by weaker attackers, I don't think it ever happened to me (and I've played like 90 games or so). So again, you have some serious and strange problems there, mate.
Goalkeepers: still one of the main downsides of a otherwise almost-perfect and still very interesting and captivating game.
GK's are capable of the best and the worse. Sometimes they make some wonderfull saves, others their awareness and positioning leaves too much to be desired. When 1-on-1 with an attacker they still get beaten in a retarded fashion in some occasions, and are still a bit too easy to dribble.
KONAMI really have to work this out.
AI Cheating: it's not true that your players will make more mistakes than usual when the AI is losing.
The truth is that the AI will become more aggressive, will tend to react quicker, will tend to dribble even more using close control, will position his players better, will make more precise and incisive passes and will be more lethal in front of the goal.
Bearing this in mind, you'll have to react accordingly, defending more actively and aggresively, avoiding risky passes, hasty moves, etc.
So, it's really up to you if you wanna get cheated by the AI or not.
Yesterday I trashed Fulham 4-0 (with Newcastle / Master League / SUPERSTAR level). The AI tried to 'cheat me' as you said... well, guess what, I used the so called 'cheat' against it.
Fulham came charging at me at full gas, but they didn't even afford to get thru my defensive midfield for like 70% of their attempts, as I made my players stand ground, and made the forwards track back everytime they attacked me.
At the end of the game, they just created 2 dangerous situations and one goal situation (Ryan Taylor made a clearance off the line in the 30th minute). I scored from 3 counter attacks and a brilliant 30 meters sitter from Cabaye, and I even managed to create 3 more GOAL SCORING situations from counterattacks, so the 'cheating AI' could have been even further humiliated in that game.
AI controlled players aren't not unstopable AT ALL. Tackles are a veryh delicate part of the game, so one have to be very careful when to tackle or when to just jockey and pressure.
Make much use of the 'Call Teammate' bottom and learn when to press the 'Apply Pressure' and how to choose the right moment to change the cursor to another defender.
The three aspects I mentioned are the fulcral part of my defending, and mastering it has worked wonders for me.
So once again: pratice a lot, coz obviously you suck at PES 2012.