I think SnowJewel hit the nail on the head. There is absolutely nothing wrong with saying, "Look you arses, if you ain't gonna listen, I ain't gonna die - so I'm gone!" There is nothing that says you must continue on with a bad group, and there have been situations when it's been obvious that the group just isn't capable of making it. In those situations I've told the group (as a Cleric) "look, we are in over our heads, we need to turn around and go back."
Secondly, you need the proper preparations. That means you need to seek out those who are selling potions and wands. It means you actually need to spend your gold and use those materials when you need them.
I like to think I've grown to be reasonably good at NWN since I've come to EfU. In fact, at the least, I know my knowledge of the game and my ability to handle situations has improved dramatically. This is in a large part to trial and error, and letting people who do stupid things while being prepared to save my own ass if things go bad.
I don't place the responsibility on others, I place it on myself. If I fall into a bad group, and I die its my fault for keeping with that group. My last character was a Rogue/Ranger/Wizard and he didn't die primarily because he was prepared. When he saw people rushing forward, he stayed back. When people started dying, he went to hide. After all, someone has to retrieve the bodies, right? Better to be the one to retrieve the bodies than to be one.
However, I do agree in that I dislike joining random groups past level five. At that point the stakes get pretty high. It's pretty easy to get to 5th level, but once you get past 5th that is when things start getting dangerous. By that time I normally have a group of individuals who I know can handle themselves well, that my character knows IC and that I seek out when I want to go questing.
My pet peeve, and this is especially true as I'm playing a pure cleric as my current character, are players who expect my character to hand them my deities blessings as if they were entitled to them. That isn't something my character normally does IC unless she sees it to her advantage (read: her survival). She blesses herself, and THEN looks around and asks "Should I save this blessing to spontaneously heal someone that I need or should I cast it on someone else?"
Mostly, this pet peeve involves healing. I meet a lot of players who simply have no healing what-so-ever. I have no idea why this is... I sell potions and divine wands, there are NPC vendors that sell potions... why do they not purchase some of them? What are they doing with their gold? It OOCly frustrates me if I have to save someone else's life by expending my own wands and potions, and do not receive compensation for the expenditure of my resources. I won't willingly let another player die if I can help it, but I've certainly had players running around with almost no health at all only saving them at the last moment. I refuse to expend my resources on people who refuse to expend their own.
I'll happily sell people potions and wands cheaply, especially if they are willing to RP with my character and give my character incentive. I will even happily sell potions at cost to players who let me know in advance what they need, and we have time before a quest. (Meaning I have time to make the potions/wands and then rest before leaving.)
Now that I've written all this I think from now on, when I do quests, I am going to hand out rewards to those who earned them the most instead of dividing things equally. It might cause some OOC hard feelings, but I think ultimately it is more fair and will force other players to work harder and contribute more.