Well, to go with your example of a fast talking V (disregarding whether this is actually a possible way to build your character in game): if you take "talking only" but still "must be prepared", you run the exact risk I am worried about. If you take "Fast Talking" to level 6 and "Handguns" to level 4 (just in case) and then run into a bunch of "Fast Talking 8" challenges, your mild focus on fast talking won't help you and you would be forced to resolve things with your fighting skills, which are not great since they are only meant for backup. If, on the other hand, you just maxed 1 of the two skills instead, you could either solve the encounter by passing the skill check or by fighting it out with your much improved combat skills.
From what we have seen, skills do not operate on a % chance system, so you either have the required skill level or you don't. If there are no "partial success" benefits to having say half the required skill level for a check, then you might as well not have put any points in the skill if it is not up to the level required. If every network in the late game requires maxed hacking skill to interact with, you either max the skill or you put nothing into it, as anything less than passing the skill check does nothing.
Can easily be solved, by having attributes/skills level up by doing their appropriate actions, similar to the Elder Scrolls games, or even GTA. That way the player can "train" his skills anytime he wants. That also seems to be what CDPR is going for. They have said, I think multiple times already, that we will be able to do training, like with the boxing dummy from the trailer or going to a gun range.
So, leveling up the attributes/skills will not depend on your story progression.
From demo Jackie didn't do nothing special, he acted like any companion from witcher 3, and why would companion doing some stupid shit be good or fun for us in anyway?
Jackie refused to sit, when they were at the gangs hideout, remember? He basically provoked the gangers, and the player got a dialog option to either tell him to sit, or to ask him what's wrong. For the demo they chose to tell him to sit, which calmed down the situation. But I wonder, what would happened with the other option, or maybe even saying nothing and just see how it plays out? But most importantly, Jackie behaved in context of the current situation, according to his character traits, which apparently includes some sort of... authority problem?
Don't know about you, but I find CDPR's approach much more appealing, because they
show who the companions are...
...instead of just
telling through boring dialog, where they just utter generic opinions. Think of Mass Effect 2, the damn whole cast of companions basically just sit around on the Normandy, mostly
telling us who they are in lengthy dialogs between missions, and every single one of them just had a few, rare missions in which they actually did
something at all.
Most of the time, they where just mindless mercenaries, just lending us their skills in combat, being easily replaceable with each other, cause they rarely had any impact on missions.
That's why I never got to the end, it was just soo boring. And I barely remember any companions. Aside from Garrus, cause his recruitment mission was really cool. Or Miranda and Jack, mostly because they had beef with each other, and Jack was kinda the most interesting character to me, because she had potential to cause trouble. The rest? I don't even remember their names...
...and Dragon Age, they pulled the same shit with companions, mostly sitting around camp, waiting for the player to start dialogs, and standing idle as mercenaries. I don't remember them at all.