I suppose one might say he is a wuss (or, more accurately as has been since said, angsty) for caring so much for the things he lost, and keeping such near ties with things that he cannot get back. And yet...
Considering how much he suffered - being thrown into a fully alien time, and (at first at least) descending from a high prince of the preeminent kingdom of mankind to a lost child amidst monsters - I think some allowance must be made that it is not angst, but rather trauma that unsettled his mind. He is slightly mad, that is crazy, but not filled with angst or insecurity. Simply put, he's slightly insane, driven to madness by the darkness that surrounded him, and his nearness to Lavos in the kingdom of Zeal. Just like one might consider Axl Rose, or similar people, insane and un-reliable, wont to become wrathful - or conversely be kind - at odd times, as their whim - or rather mind - will have it.
Now, even without this pre-supposition of madness, I think that an over-mastering wrath for vengeance cannot be counted as angst or as being a wuss in all cases, and likely not in his. We do not hear him complain about his lot, per say, crying 'oh, woe is me!' even. Rather, he knows what has happened, knows it to be his lot and fate - notice, he does not even attempt to avert it in Zeal! - and accepts it, looking rather to vengeance and redress in light of it, the death of his foul opponent who dealt him that hand. Moreover, some leeway must be given to him in light of heroes of other sagas who have woe-swept times overcome them. In contemporary stories, think of the spaniard from the Princess Bride - a person that I saw somewhere Magus be compared to, and not without reason. He is driven by vengeance for the death of his father. He says, at least in his youth, he mourned his father, for he loved him, but then devoted his time to vengeance. That is his sole purpose. When it is complete, he wonders what to do, for that single quest has been his purpose so long, he is bereft of purpose with it gone. As I said, somewhere I saw Magus compared to the spaniard, and it is a very good comparison. Just as the spaniard (Inego Montoya or something like that, isn't it?) is not angsty or a wuss, neither is Magus - Magus is only a measure more cruel. He does not do this for his own assertion of power, but for vengeance, which itself without any other requisites is a powerful force - spirits of vengeance, and the concepts thereof, feature into the orders of the world in many ancient cultures. Maybe Magus was even compelled by some ancient duty of blood-vengeance that held in Zeal - but that we will never know. Further comparisons might be made with numerous other people in tales. Say, another spaniard, the hero of Gladiator, Maximus. He has everything torn from him - his position of honour, his family... his life, I think, he would have counted a small further loss. He weeps for the death of his wife and child. He hungers for the death of the one responsible, yet I do not think he will be considered a wuss, either.
Yet further examples may be taken in older literature. Take Akhilles. He, in fact, weeps bitterly, the night long, at the death of his friend Patroklos. It stirs into his mind such fire that the next day his wrath is bitter upon the hosts of Ilion, driving them back to the river Skamandros - where he even assaults the river itself! - and finally back into the walls of their own city, with only Hektor left outside, who promptly flees in a run about the city. When he faces Akhilles, he is swiftly killed. Now, Akhilles is a standard of ancient hero, one to be looked to and emulated - so the Greeks might well have thought. But as I have said, he wept bitterly. Moreover, his fabled feud with the king Agamemnon was not for any love of a girl - truly, he could have cared less, I think; after all, he had a wife and a son already, the latter of which fought at Troy - but for his injured position, his Arete as the Greeks called it, his warrior's standing and prowess amongst his peers. Agamemnon took this away from him, pushed him around as it were, and Akhilles would not have it, swearing bitterly that he would not help his fellow Akhaians unless the fire came to his own ships upon one wing of the host. Now, is he a wuss for this? Plainly, it is the form of the ancient hero. Any of those combatants of the war would have responded negatively to a thread against their Arete and a question against their valour. This would have been a standard view in the ancient world. Now, is this being a wuss, or just a societal difference? Maybe the same holds true for Magus.
