1) CHOO CHOO! :3
2) True, will come eventually, from places such as Spelunker's Lodge. But even before that might make it have chance to drop from mountain from normal attacks if damage and luck are high enough.
3) Agreed, I thought of making Rune of Speed and Rune of Machine also work on Bulldozers, but those runes are already super good, especially late game with so many runesmiths, so I thought it might be better to find new angles, but the problem is there isn't any room left in Forge for new upgrades. So I might just add them to Manufactorum instead. (Unless I have advanced forge building, or have wizard's tower have most of the rituals/enchants which then leaves room in the forge. We'll see.)