Ok, So I haven't figured out one-ways.
Turn restrictions seem to be an in-progress thing.
And JOSM is like looking at "the city by night".

I've looked through the wiki for further info on one ways, but no joy yet.

On the bright side, I've filled in lots of Sheppard Ave and Wilson. I have to figure out how to erase a way, because Finch Ave runs from where it really physically intersects Yonge Street along to the 401, parallel to Yonge. Trust me, it's not there, but I don't know how to fix it -- yet.