Oh he's not that bad! :)
He's supposed to get the Hobbits lost on the way to Rivendell...so the Black Riders can't find them. It's not like he had no clue where he was. To me, choosing the Cadharas route is saner than trying Moria. So that plan didn't work out. It happens (expecting Aragorn to be omniscient is a bit much).
He doesn't know whether to go with Frodo or with Boromir at the end of the Fellowship.
Well, Frodo. I fear that the burden is laid upon you. You are the Bearer appointed by the Council. Your own way you alone can choose. In this matter I cannot advise you. I am not Gandalf, and though I have tried to bear his part, I do not know what design or hope he had for this hour, if indeed he had any. Most likely it seems that if he were here now the choice would still wait on you.His decision depended on Frodo's decision.
As for the angst at Boromir's death, would you want to follow a leader that didn't care that one of his companions died?
In the book, he leads the Hobbits off the trail from Weathertop, but then he gets lost. (Which I would too if I were in the woods... don't follow me, I need street signs)
After Boromir's death, the angst isn't about Boromir, it's about Aragorn. Everything I do comes to nothing...
You're right about waiting for Frodo... he couldn't really decide what to do until then. But you don't get that in the movie. In the movie, he was following Frodo to the end. It was only after the confrontation, that he let Frodo go.
The movie Aragorn is more sharply drawn. But, you have to do that in a movie where you are just one of 9 supporting characters. In the books, I have pages to devote to angst and self-doubt. That's what makes his transformation after looking in the palantir so amazing.