I am aware of how tactical games work.
I go to have my tank aggro the enemy, before my other guys can even get to him to help him attack, he dies.
Or lets say that I decide to have them all back up the main guy from behind and stay close by. Well that doesnt work because as soon as they all beat one guy they IMMEDIATELY find another guy to attack. When I try to press the hold key to make them stop, then they just fucking stand in place and get waylayed on by demons until I try to change over to them to control them and by that point they are dead. And yes, thats even with the pause feature. Which should not even have to be implemented if you're doing a proper Action/RPG.
The game tries to be both an action game and an RTS. And it completely FAILS at both genres.
And as for rogues? How in the HELL can you backstab someone from behind when you cant attack while moving, and you have to reselect your enemy when you move, except he moves and you miss him and end up targeting an empty space to move in. All while the fucking demon mage is blasting you with fireballs to oneshot your fucking main character.
I have had my full party wiped every single time I get into the woods, just because of the PISS POOR excuse for AI, dumb as bricks tactic system, and enemies with WAY too much health for a starting area.
And FYI, Dragon Age 2 is only SLIGHTLY better because they have the attack nearest enemy button, but what kind of Action RPG game doesnt have fucking CONTROLLER SUPPORT in this day and age? Absolute bullshit.
Like I said, I was able to do it just fine on hardest difficulty, and I'm not a hardcore gamer. So clearly it's not as impossible as you claim it to be.
Let's go your points 1 by 1:
1. If your tank cannot take the heat, then get it off him for awhile. Knock an enemy down and stun a different one, while backstabbing the third one with your rogue, then freeze a fourth one. That's four guys off your tank, making your tank more survivable. You said you're using the pause button. Clearly you're not. That is so easy with pause spamming. All you have to do is watch when enemies become disabled, remember who you just ordered to disable that person, then immediately order them to do something else. Once the enemies recover, you've slowly gained a numerical advantage so do the entire thing all over again. As the game goes on and your tank gets tougher, you'll find yourself essentially putting it on taunt auto-pilot. Heck in the endgame I can solo the game with a arcane warrior-blood mage. Or an agility rogue.
2. What the developers were clearly trying to do here was implement a version of the Baldur's Gate/NWN style combat, except with less focus on the rounds, and more on the real time. Not an action game or an RTS. A Western RPG (as opposed to a JRPG). They did it really well.
3. On rogues: What the hell is difficult with ordering a rogue to go to someone's back, watch when he gets there, pause, then order him to attack the guy whose back is on his face? Sounds pretty simple and straightforward to me.
4. You explained your difficulties well, but you're not really telling me how you're doing crowd control. Seems like you're just letting the computer do it all for you.
5. In order to maximize the game, do not trust the AI. At least not at the start. The AI gimps mages and rogues. Like I said, I turn the AI off for the highest difficulty. It just gives you a false sense of security. I only use the AI to keep my ranged characters at ranged and melee characters at melee.
6. Apparently, you're playing a console version. My experience is that consoles suck for games of this kind, and in DA:O, the PC version is vastly superior. So that may be half your problem. EDIT: IIRC, the console versions had gimped difficulty in order to make up for the inferior controls. Console difficulties are equivalent to the one step lower difficulty than the same difficulty in the PC version.