To start, the tatics system is fairly limited. No matter what, you'll end up micromanaging your party most of the time. In regards to your specific issues:
Nyphlah wrote...
Here's what I'd like to accomplish for the party:
* If your about to die, go ahead and drink that potion
This you can do -- "If health < 50 %, then drink health potion". This should be near the top of your command list, to ensure that it has priority over other actions.
* Attack what the main character is attacking
Doable -- the condition is under "Currently Controlled PC" or "Main Character", depending on how you want to do it.
- don't run up the stairs into that crowd of darkspawn until we're all ready
How is the game supposed to know when you are "ready"? One option is to use the "Hold" command (PC this is "H"), but this prevents the other characters from following the controlled character around. Even then, you have to manually release it when you are "ready".
* If there isn't anyone around you, go ahead and use your ranged attack - it's okay, we're not short on arrows
This is doable, but it takes more tactic slots than what you have. Fundementally, you'll want to check the range to the enemies, if nothing is close switch to ranged weapons, then attack.
* If your under 10% health, run for your life *away* from combat (again, no need to go up the stairs just yet!)
The AI supports a "run away" command, but it isn't enabled in the tactics you can select. The reason is the second part of your comment -- how is the game supposed to know which directions are "safe"? The answer is that it can't, so you'll have to disengage by hand. Keep in mind that in many cases attempting to disengage is suicide (because the enemy will follow you).
* Fight with your back to a wall (or corner) rather than stand there and let two guys backstab you while you assist the tank. It's hard to focus when there's a greatsword in your lumbar...
This isn't possible with the tactics system. It is highly questionable if this is implementable at all, even given a full SDK -- assuming that all opponents are not in the right place (and they won't be), how do you determine when it is appropiate to retreat against a wall and when it isn't? Which wall should you choose (the closest wall might be behind the enemies). Moving "against a wall" might expose other characters to attacks, defeating your whole strategy, which would be very fusturating.
* If you have a special ability up, use it; that's why I bought it
You'll need one tactics slot for each special ability that you wish the NPCs to use (minimum). If there isn't an explicit tactic to use an ability, then they will only use it when you explicitly order them to do so. In many cases this is
good -- you may want to save a key ability until the character is in the right position to deploy it for maximum benfit, which is very situational.