Does anyone know if increasing your improvement passive (white>gold) allows your hireling to deliver higher mats like your rank in the crafting skill does? Or is it only determined by the hireling rank?
You do not need item improvement passives to earn better hireling deliveries. You get better deliveries by increasing the base passive that allows you to craft better items, and more points in hirelings increases delivery size (and therefore chance at Rare items).
But...for those hoping to get gold tempers from hirelings...it happens, but it's extremely rare. The primary source of gold mats from hirelings comes from collecting the raw ore, and converting that. If you log once per day you get about 4 raw ores, so after 50 days you'd have 200, which result in about 2 golds. Therefore, the gold mat rate breaks down to about one per daily logging character per hireling.
Agree with the above poster, and just wanted to confirm that hirelings are not a reliable source of gold tempers. I'm lucky if I see 1 gold temper in 2 months of twice daily deliveries from 4 separate hirelings. Hirelings are most useful for the gradual supply of basic mats that can boost your stock if you don't do too much crafting.