Having a few characters without serious psychological issues would be nice. I feel that these days many people confuse interesting with insane characters. The kind of hero adored and praised by the ancients would be considered boring and 'one dimensional' today..
I doubt it. Achilles was a major asshole, so was Odysseus. I doubt either one would fit into polite society today.
I do agree it would be nice to have a few companion choices without psychological problems, and maybe we'll get that with the remaining companions we haven't seen yet.
Also, I wouldn't put Lae'zel in the category of psychological problems. She's a non-human warrior from a heavily martial culture who considers everyone not from that culture to be inferior. A Spartan, basically. She only has "psychological problems" from an outsider perspective.
Lae'zel is actually probably the closest to the more 'ancient' depiction of heroes. Which certainly makes for an interesting, if abrasive, romance option.