Technically you both have ©, if you both edited it. Osmarender attributes the 'copyright' to the last person to touch a way, even though it may be just a tiny edit.

And, yes, JOSM does have a steep learning curve, but once you get used to it, its quite a quick editor.
I usually find it best to keep one hand on the A and S keys to quickly switch between adding mode and move/select. It also allows for quick access to the meta-key-modifiers (unsticky the adding of nodes, new way, dont connect etc), Ctrl-Z (undo) and Alt-A (add a tag)

No, living_streets are not rendered at all, however, mapnik picks up the name and oneway tags and renders them as it would for any highway.

Woah, yay!

Looks better quality than I currently get through JOSM with the WMS server.