Is it intentional? As I understand it, some of my units, esp Borden and Ransom, like to rush into a firefight with no thought to safety. Also, pathfinding stupidity seems to be prevalent in some souls, although I didn't pay attention to who specifically
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Also, I noticed Patton is usually the dumb one who tries to fire at enemies behind walls. He seems more stupid than the other souls I have.
Anyone to verify this?

Well, the Tex Murphy games forced me to put my campaign on hold. I'm partial to adventure games, specially old ones so it really couldn't be helped. Everything i was playing got bumped down 3 knotches, including this one.
Rushing into combat: Usually i don't let them go wild into combat by cancelling their previous orders and issuing new 'hold position' orders. But yeah, if left unwatched they all tend to go a little crazy...
Pathfinding : land vehicles definitely have some problems with pathfinding. Instead of direct 'go here' 'go there' orders i use sensible waypoints to get the land units where i want them. I don't know if this is specific to any souls, but i do have the impression that the souls all around performance improves (more noticeable in combat) when they get assigned to a vehicle relevant to their profiles, like say, having Ransom on a land vehicle or Patton flying around in the sky it's a damn waste.
That's one of the reasons i extracted all the profiles. HAving them handy makes assigning the right soul to the right vehicle a little easy untill you manage to memorize all the souls profiles and relevant backgrounds.

Yup. I do the same too. The game is great in everything but the AI. You really have to hold their hands at times, sadly. You're right that different units behave differently in combat. Arming Patton with a Warhammer makes him much more confident when taking on hostile units. Ransom is also very maneuverable in a chopper, more so than others.
Sadly, that's where the positive side of the AI stops. Some of the really annoying things I found with regards to AI:
- Bad pathfinding. Like you said, you really have to hold their hands and issue waypoints to get up a certain place, but even then, when climbing mountainous areas, the AI doesn't agree with me that a perfectly viable route is possible to climb, hesitating before telling me it's not possible
- Other times, when I have a group of units arranged in a doorway, and I order an AI outside to proceed past that doorway, it refuses to just push away that group of units, instead choosing to try to bang the wall - which once again results in them telling me it's impossible to proceed
- Then of course, if you don't tell them to "Hold Position", they usually run all over the place
- Even more incredibly was how the developers actually managed to overlook a "Hold Fire" button. Patton was so trigger happy with his Warhammer, he didn't care that there were friendly units around his targets, and ended blowing up Borden while she was surrounded by aliens
Shame, because otherwise this would have easily been one of the best games I've ever played

i found the ai pretty good on the whole, especially for an old game.
Pathfinding up hills could be tricky, but some of those maps are really really hilly... i had some trouble finding viable routes myself.
The only thing that bugged me was that air units didn't seem to be able to avoid AA towers... and they get chewed up by those REALLY quick. Ransom in particular is far too gung ho at times....
You defintely need to make use of the hold position, move to, and attack to options carefully, to prevent a few of them going off on one-man crusades...

Borden loves demolition, and she propably gets too excited sometimes. Ransom likes to rush at AA towers, and he's very aggressive.