1) I don't have a hot glue gun, but I do have string, so should I just use superglue to hold the string in place?
2) Also where could I get a replacement spring for it?
3) Should I use white lithium grease or silicone grease?
4) Also nice hopper clip and i'm guessing that you used the string idea with it too.
1) String and super glue should work fine. Even without glue, I'd thread it through small holes and tie the ends together.
2) McMaster-Carr is one of the better sources, though some hardware stores have selections.
3) Always silicone. Lithium grease is better than most, but if you have the choice, use silicone.
4) Actually, no, hadn't bothered with that yet.