Is Fortinbras Right In His Assessment Of Hamlet?

In my opinion, Fortinbras could not be more wrong on his assessment of Hamlet.
He claims that Hamlet would have "proved most royal" had he been given a chance. 
If you look at everything that happens within the play, there is nothing kingly about him!!
The first thing Hamlet could have done that would have been royal was prevent the too-soon marriage of his mother and his uncle.  A royal may have stood up for what he believed was right (not adultery, in this case) and now, being the protector of his mother after his father's death, put his foot down and said "No!  It has only been two months since your husband, my father, died.  I demand you grieve some more!"
That would have been very royal, and many may have held him in a very high esteem.
Even if he didn't put to rest the idea of his mother's remarriage, a good, noble thing to have done would have been, having learnt of his father's murder, to have chopped Claudius' head off in vengeance (something which would have been respected and honoured in the day of the play).  Instead, he does something which seems meak and weedy, and pretends to go insane.
The author of this does not in the slightest see how madness would help in this situation.
Fortinbras must KNOW that Hamlet went mad.
So how has he come to the conclusion that Hamlet would have made a fit king?  Ridiculous.
The next thing Hamlet does that I disagree with is the fact that, whilst mad, Hamlet bares himself infront of the woman he has seduced.  That is not in the least royal, regal, noble, or however you call it.  This is humiliating for Ophelia, and not even a tiny bit dignified, which kings always seem to be.
So Hamlet is being highly unkingly now, and continues to be for the rest of the play.
In actual fact, the only good things that this author can see about Hamlet is that he does want revenge (yet goes entirely the wrong way about it), and then has a duel.
The duel is a noble thing to do.
I'm unclear as to the reason they duel.  Possibly for Laertes' father's honour, or Ophelia's honour.  But I'm not sure.  At least this part is in all fairness.
This is the only part however.
The rest of the play is spent with Hamlet dashing about the castle acting like someone out of an asylum, when he could actually be doing something useful with his time, like defending his father's honour, ending his mother's adulterous marriage, or, and this would be the best ending in my opinion, getting Ophelia's hand in marriage, forgetting the whole affair with the murder and the adultery and the throne, and taking Ophelia off to somewhere nicer, or warmer, and marrying her there, having a whole bunch of good looking babies, and being generally happy with life.
So no.  Fortinbras is NOT right in that Hamlet would have made a great king.  He was a philosopher and a pansy.