The first thing to note is that the world of Pal Tahrenor does not use gold as currency. There is a system of coins called bishani which has been made universal through use of magic. You can read more about them here: http://www.tharshaddin.com/wiki/Currency
Trolls possess a healing ability I will need you to add, unless there is any particular reason Mograg doesn’t have it. Perhaps he belongs to a subspecies which lacks this ability. You may want to read our page on Trolls: http://www.tharshaddin.com/wiki/Troll
We’re going to need more detail in his strengths and weaknesses. You’ve written what amounts to a single half-sentence for each one, which doesn’t tell us much about his actual capabilities.
Here are some examples of applications which have the kind of depth we expect from strengths and weaknesses:viewtopic.php?f=15&t=3446viewtopic.php?f=15&t=3091viewtopic.php?f=15&t=3649
Notice how they spend a paragraph or so detailing exactly what makes their fighting skill what it is? There is a great deal of emphasis on what is or is not within a character’s capacity, particularly as compared to an average human being. The particulars are outlined clearly.
“Physically powerful, capable of massive feats of strength”: what are the limits of his strength? Just how strong is “massively powerful” in relation to humans?
“Thick warty, leathery hide and feels little to no pain from most wounds”: Pain tolerance is fine, but feeling no pain is absurdly powerful. Assuming one did not have access to fire, as can be expected in most situations, is there any way another character could stop Mograg from accomplishing something? We’re going to need more information on what level of pain he’s capable of tolerating.
“Has animal like cunning in certain situations”: This could easily be abused to spider-sense levels of clairvoyance by predicting all harm coming his way. In what situations is he clever? What does this ability actually do for him?
As far as his weaknesses go, I’ll also need more detail. Once again, a half sentence declaring a trait will not provide anyone with the nuance required to represent a person. Furthermore, I fail to see how most of his weaknesses actually hold Mograg back. He seems perfectly content with his present situation, and weaknesses need to be in opposition to a character’s goals to work.
Fire just prevents a troll’s natural healing ability. While you should leave it under weaknesses, all it really does is offset a strength. Unless you choose to mention he burns far more easily than the average human or has some terrible phobia, this doesn’t really set the character back in any unusual way, which is what weaknesses are. I’ll note that, as written in your history, he was capable of taking on a man armed with a flaming halberd with next to no difficulty or long term-incapacitation.
His youth isn’t really an issue. You’ve already mentioned a lack of intelligence and he currently possesses an “animal cunning” which could fill in for experience in a pinch.
Being socially unskilled (we see that one a lot on fighting characters) and stupid doesn’t really prevent one from working as a physical bodyguard, which is a fairly straightforward job of “don’t let pointy things go into this person.” You’ll need to describe in what ways these actually hinder him.
To generalize what I’m saying above, it is worth pointing out that currently, he is a troll. That’s basically all his is, a big troll. There is nothing that sets him apart from every other member of his species, he has no higher aspirations than what he already possesses, and generally lacks character traits beyond what would be expected. While it is true that trolls are big dumb brutes and you should keep these traits on him, it would be worth your time to consider what makes him unique and worthy of player character status, instead of some generic NPC bruiser.