Roads and rivers are in different pieces because that's how they come out of rpg city generator...plus, each segment has a different width value, so if it was all one piece they would all be the same width without me changing how the svg is structured somehow...

Can't remember offhand, but editing the nodes in inkscape probably needs you to "ungroup" or "break apart" in one of the menus.

You can select all the same fill/stroke colour in inkscape by selecting the object type you want so it shows in the XML Editor (edit -> XML editor I think), copy the colour value and paste it into the style box in the search box. Or something like that anyway.