0. Please use more descriptive comments, and upload them in different changesets 
1. Please don't blindly accept any editing software suggestions. That's lying to validators. You should at least read the "warning", which tells you Mei Foo Roundabout should be split. `layer=1` at the same time conflicts with many bridges along. 
2. Why are you changing `=viaduct` to `=yes` as well? 