Thanks for translating! :) Here are some humble suggestions:
"als Außenseiter hast du's schwer" works in English too: "As an outsider, you've got it hard."
"Ach hättest du nur ein Gewehr" should be "Oh, if only you had a gun."
"du bräuchtest einfach nur die Waffe zu laden" should be "You'd just need to load your gun."
"You're already doing great in it" would be something we would say about a class someone's in, but for one little task we would say "You're already doing great at it."Because the "das" has been moved to the beginning of the sentence and a "ja" has been added, the German sentence is emphasizing that 'loading a gun' is the thing the kid is good at, implying that there might be other things it would be better to be good at. You could do this in English by saying "That's something you can do just fine" or "At least you've got that down."
"auch wenn hier alle sterben" might be more like "Even if everyone here dies."
"Nothing will stand in your love's way" is not incorrect, but using " 's " to indicate the genitive case is more usually done for living beings, so here it sounds a little bit too much like "nothing will stand in the way of the person who is your beloved." I think it would sound better if you said "Nothing will stand in the way of your love."
Haha =)) :p.