I like him, i like his style but His Tuvok rescue team came back injured like hell, one losing an arm. He lost his chief engineer. In #2 He is put in a position where his Chief of Security/Chief Tactical officer (who was in a coma for a while) was forced to leave a fellow crewmeber behind on another rescue mission. He is going to Let Donatra get away with murder twoce
**Spoiler warning for the Titan books**
While I see your points (on the surface it does reflect badly on him), the problem is that, that is just on the
surface. In every one of those situations, the question is what could he have done differently? I believe the answer in all of them is: Nothing. Tuvok's rescue was a necessity and exactly how brutal/difficult it was was out of his hands. The fact that he rescued Tuvok with that minimal of injuries to his crew speaks well for his ability to lead in that his team is well trained, well organized, work well together, and he chose them wisely.
I don't recall the circumstances under which he lost his engineer, but I don't recall him being able to do anything about that either.
Leaving a person behind is never something a team like that wants to do, but there are many many cases where it is what MUST be done. Having the ability to make that call is what makes for good leadership, sacrificing one to save a group is terribly horribly difficult but is the right thing to do. A good leader can and will do it and then fret over it later and the decision will always come back to haunt the decision maker.
As for Donatra... Well this one is a double-edged sword because now you have diplomatic relations with a neighboring empire that (while weak for now) is still not someone you want to make enemies with, especially with the Federation actively trying to make friends with them. Cases like this you have to analyze closely and make decisions as to what ends up making the better outcome? Which is the lesser of two evils? Sacrificing your ideals for justice and making an enemy a friend? Or making enemies of a people who could no doubt cause much greater harm that she did there in the name of justice for one? Also IIRC he didn't have the proof needed anyway to actually make the accusations. So accusing her of something he couldn't prove would have been
very bad.