Thank you for the feedback. Having the tile information in a tool tip was an idea that I had but I wasn't able to get it working quickly so I dropped it in favor of getting things done. I'll try to put it back in for a future update.
I'm not sure about lowest possible scores, things were kind of just thrown together towards the end. The lowest travel times I'm seeing are around 110 days and the lowest gold is 141 by only moving on the four maps that actually need to be moved.
Generally the gold was the intended optimization value, so I left a large gap for people to cost themselves more money needlessly, but really the 150 days and 1000 gold were just randomly chosen as nice round numbers.