Balthazar's Appearance

The game states that Balthazar's "light" was diminished, meaning he lost his power as a deity, but not total loss of his fire powers. If you look at Balthazar he looks a bit aged. Could Balthazar losing his godhood have caused him to age, or does he look the way he does naturally?

This is unsure. We only get to see him in this current form. before Season 3 he was only shown in pictures and statues. Most depict him wearing armor. A mural in Gandara shows him without a helmet, showing a rather old man. This was in the time of GW1 and so atleast 300 years ago.https://wiki.guildwars2.com/wiki/File:Balthazar_mural_(Gandara).jpg

Some murals and concept art do depict him as though he could be lanky and aged beneath the armor:

https://wiki.guildwars2.com/wiki/File:Balthazar_concept_art.jpghttps://wiki.guildwars2.com/wiki/File:Balthazar_mural_%28Gandara%29.jpghttps://wiki.guildwars2.com/wiki/File:GDC_2010_Temple_of_Balthazar.jpg

Given that Dhuum has remained imprisoned for over a thousand years in a similar state as Balthazar, I'm hesitant to say Balthazar began aging after losing his divinity. He may not have been a god, but he wasn't human either, as showcased in his death scene.

I would not think they ages, godhood or not, the gods are just what the humans call them, not a direct reference to the amount of magic in them and anything special in the magic that they held

and their appearance really depends on the person and their own interpretation, no human can look at a god directly cos of the vast amount of magic in them (kinda begs the question, did Dwayna seduced Grenth's papa? ?) so human's depiction of the gods differs

the fact that the commander was able to look at Balthazar and kill him is an indication that the magic he had absorbed was certainly not enough to deflect attacks from mortals; Sohothin helped, but I don't think it is the reason, Balthazar would not be stupid enough to give away his achilles heel

I suspect that the gods have some degree of control over how old they look. Certainly, Melandru is said to be the oldest of the gods, but she still looks like a young woman, at least according to the statues and murals.